JP2008194940A - Ink-jet recording head and recorder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve printing quality while absorbing a difference in temperature between boundary portions of chips and preventing degradation of printing quality due to density variation in an ink-jet recording head having a plurality of recording element substrates arranged therein. <P>SOLUTION: The difference in temperature between the boundary portions of the recording element substrates is controlled by arranging heaters on a recording element holding substrate having arranged thereon the recording element substrates by corresponding to the respective recording element substrates or the boundary portions thereof. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a recording head and a recording apparatus that perform a discharge operation of a liquid used for recording onto a recording surface of a recording medium.

  The ink jet recording apparatus is a so-called non-impact recording type recording apparatus. High-speed recording and recording on various recording media are possible, and there is a feature that noise during recording hardly occurs. For this reason, it is widely adopted as a device that bears a recording mechanism such as a printer, a word processor, a facsimile machine, and a copying machine.

  Recently, the amount of data to be recorded has increased, and especially when graphics and the like are printed out, higher speed recording has been required due to the large amount of data. A so-called full-line type ink jet head in which discharge ports and electrothermal transducers are arranged in a long length over the width of a recording material and an ink jet apparatus including the ink jet head are highly expected to improve the recording speed described above. .

  Inkjet recording is a method in which minute droplets are ejected from minute ejection ports and recording is performed on a recording paper. A typical method is a method using an electrothermal conversion element. In an ink jet recording head using an electrothermal conversion element, an electrothermal conversion element is provided in the nozzle, and an electric pulse serving as a recording signal is applied to this to give thermal energy to the recording liquid, and the phase change of the recording liquid at that time The bubble pressure at the time of foaming (boiling) of the recording liquid caused by the above is used for ejecting recording droplets.

  A conventional example will be described with reference to FIGS. A plurality of ejection ports 202 for ejecting ink are opened on the surface side near the center of the recording element substrate (chip) 201, and a heater (not shown) for foaming ink corresponding to each ejection port. It is formed on the recording element substrate 201. In addition to the transistor circuit, the recording element substrate 201 is mounted with a logic circuit and a temperature sensor for driving the transistor. Wiring such as signals for driving them is connected to the flexible film 203 by wire bonding or the like, and signals to individual recording element substrates are electrically connected to the outside.

  The periphery of the recording element substrate 201 and the electrical connection portion of the flexible film 203 are covered and sealed with a sealing agent 205 excellent in sealing properties and ion blocking properties such as epoxy, fluorine, and silicon resins. .

  An ink flow path 207 formed by the recording element substrate holding member 204 and the support member 206 is provided in the back surface side of the recording element substrate 201 so as to extend in the nozzle row direction. A slit 208 is provided for supplying to the surface side.

  The ink flow path 207 is configured to receive supply of ink from the outside of a head (not shown).

Moreover, as a prior art example, patent document 1, patent document 2, patent document 3, and patent document 4 can be mention | raise | lifted, for example.
JP 2005-066930 A JP 2005-178306 JP JP 2005-193497 A JP 2005-279952 JP

  In a configuration in which a plurality of chips are arranged, the temperature of each chip may not be continuous as compared with the integrated substrate, and a temperature difference may occur at the boundary. When such a temperature difference occurs, the ink discharge amount is temperature-dependent, and thus a difference occurs in the discharge amount, resulting in a density difference at the chip boundary (FIG. 6). Due to this density difference, streaks are generated at the chip boundary and the image quality is lowered.

  A heater corresponding to each chip or corresponding to each chip boundary is provided on a substrate on which a plurality of chips are bonded, so that the temperature at the chip boundary can be controlled.

  As described above, according to the present invention, in a head in which a plurality of chips are arranged to form a nozzle array, a heating heater corresponding to each chip or each chip boundary is provided on the substrate on which the chips are arranged to control the temperature. As a result, the temperature difference at the chip boundary can be suppressed and the density difference at the chip boundary can be reduced, and a good image quality can be obtained.

(Example 1)
FIG. 1 shows an ink jet recording head of an embodiment of the present invention. FIG. 3 is a partial cross-sectional schematic view of the recording head of the embodiment of the present invention, and is a cross-sectional view taken along the line AA of FIG.

  In FIG. 1, the inkjet recording head of the present invention has a plurality of ejection ports 102 for ejecting ink on the surface side near the center of the recording element substrate 101, and the ink droplets ejected from the ejection ports 102 It is for recording.

  On the recording element substrate 101, heaters are formed corresponding to the respective discharge ports 102. The heaters are energized and heated to foam the ink, and ink that is a recording liquid is discharged from the discharge ports 102 with the kinetic energy. Discharge.

  In addition to the transistor circuit, a logic circuit and a temperature sensor for driving the transistor are mounted on the recording element substrate 101. Wiring such as signals for driving the transistor is connected to the electric wiring substrate 103 by wire bonding or the like. Connected to an external signal.

  An ink flow path 207 formed by the recording element substrate holding member 104 and the support member 106 is provided on the back surface side of the recording element substrate 101 so as to extend in the nozzle row direction corresponding to each nozzle row. In 101, a slit 208 for supplying the ink on the back side to the front side is formed by anisotropic etching or the like.

  The ink flow path 207 is configured to receive ink supply from the outside of a head (not shown).

The recording element substrate holding member 104 is formed of an alumina (Al ₂ O ₃ ) material having a thickness of 0.5 to 10 mm, for example. The material of the first plate is not limited to alumina, and has a linear expansion coefficient equivalent to that of the material of the recording element substrate 101 and is equivalent to the thermal conductivity of the material of the recording element substrate 101. Alternatively, it may be made of a material having an equivalent or higher thermal conductivity. The recording element substrate holding member 104 has an ink supply port for supplying ink to the recording element substrate 101, and the ink supply port 208 of the recording element substrate 101 is connected to the ink supply port of the recording element substrate holding member 104. Correspondingly, the recording element substrate 101 is bonded and fixed to the recording element substrate holding member 104 with high positional accuracy. The adhesive is desirably, for example, a material having a low viscosity, a thin adhesive layer formed on the contact surface, a relatively high hardness after curing, and ink resistance. For example, it is a thermosetting adhesive mainly composed of an epoxy resin, or an ultraviolet curing combined thermosetting adhesive, and the thickness of the adhesive layer is desirably 50 μm or less. The recording element substrate holding member 104 has an X-direction reference H1204, a Y-direction reference H1205, and a Z-direction reference H1206, which are positioning references.

  As shown in FIG. 1, the recording element substrates 101 are arranged in a staggered manner on the recording element substrate holding member 104 to enable wide recording with the same color. For example, four recording element substrates each having a nozzle group length of 1 inch + α are arranged in a staggered manner to enable recording with a width of 4 inches.

  In addition, the end of the ejection port group of each recording element substrate has an overlapping area with the end of the nozzle group of the recording element substrate adjacent to the staggered pattern in the recording direction, so that printing by each recording element substrate is possible. The gap is prevented from being generated.

  The electrical wiring substrate 103 applies an electrical signal for ejecting ink to the recording element substrate 101, has an opening for incorporating the recording element substrate 101, and has a recording element substrate by an adhesive. The main surface of the holding member 104 is bonded and fixed. As a material of the electric wiring board 103, for example, a flexible wiring board having a two-layer structure is used, and the surface layer is covered with a resist film.

  FIG. 2 shows a recording element substrate holding member used in the recording head of the present invention.

  In FIG. 2, reference numerals 125 to 128 denote resistors, 104 denotes a recording element substrate holding member, 120 to 124 denote connection terminals for connection to the outside, and 129 to 133 denote conductor wirings. Resistors 125 to 128 are arranged around the recording element substrate on the surface of the recording element substrate holding member 104, such as ceramic, which is electrically insulating and has good thermal conductivity, and both ends of each of the resistors 125 to 128 are arranged. Are connected to conductor wirings 129 to 133, respectively. The conductor wiring 133 on one end side of each resistor 125 to 128 is connected to the common connection terminal 124, and the conductor wirings 129 to 132 on the other end side are connected to the connection terminals 120 to 123, respectively. The connection terminals 120 to 123 are connected to contacts provided in the printing apparatus, and the temperature is controlled by monitoring a temperature sensor provided on the printing element substrate 101 by a control circuit.

  FIG. 4 shows the concentration distribution between the chips. By controlling the temperature of each chip according to the present invention, the density difference (Δ) between the chips is reduced, and the density distribution between the chips can be made smooth.

  FIG. 5 shows another embodiment.

  Reference numerals 134 and 135 denote resistors, and 136 to 138 denote conductor wirings. Each resistor is arranged only at the end of the chip, one end is connected to a common wiring 138, and the other end is individually wired independently. It is possible to alleviate the temperature difference at the chip boundary even with the resistor arrangement only at the chip end.

  FIG. 8 is a schematic view of a full multi-ink jet printer using the recording head of the present invention.

  10 is a cassette paper feed, 8 is a manual paper feed. As a paper feed method, a method of separating recording sheets one by one with a feed roller and a separation pad (Dupro method), a nail separation method, a retard method, and the like can be considered. . The recording paper P fed by the cassette paper feeding 10 or the manual paper feeding 9 abuts the leading edge of the recording paper to the nip of the resist roller pair 4 that has stopped, and further rotates the feeding roller to slightly feed the registration paper 4 with the registration roller 4. By making the recording paper P slack between the feeding rollers 8, it is possible to correct the oblique feeding of the recording paper P. Further, the photo sensor detects that the recording paper P has hit the nip of the registration roller. Then, the registration roller is rotated, and the recording timing of the recording head 1 is adjusted by using the rotation start of the registration roller 4 as a trigger, whereby an image can be formed at a predetermined position on the recording paper P.

  The recording paper P transported by the registration rollers is sandwiched between the transport belt 5d and the pinch roller pair 12, and a high pressure is applied to the lower roller 12b of the pinch roller 12, and the upper roller 12a is grounded. Thus, the recording paper P that has passed through the pinch roller 12 is conveyed while being electrostatically attracted to the conveying belt 5d. The recording sheet P electrostatically adsorbed on the conveying belt is conveyed to a printing start position immediately below the recording heads 1K to 1C by a belt 5d conveyed by a driving roller 5b driven by a driving source which is a pulse motor (not shown). Is done.

  The conveyor belt 5d is stretched by a driving roller 5b, a driven roller 5a, and a pressure roller 5c, and the pressure roller 5c has an arm (not shown) whose one end is swingably attached to a conveyor belt housing 5e (not shown). The end is rotatably attached to the end, and the arm is pressed by a spring to apply tension to the transport belt 5d.

  1K, 1Y, 1M, and 1C are full-line type recording heads in which a plurality of recording elements are arranged over the entire width of the recording area of the recording sheet P, and 1K (black), 1Y (cyan), 1M (magenta) and 1C (yellow) are arranged at predetermined intervals in this order, and the recording head 1 is attached to a head holder 2.

  In the configuration as described above, the recording paper P is attracted to the upper surface of the transport belt 5d by electrostatic attraction, and is transported by the transport belt 5d while being printed by the recording head 1.

  A paper discharge roller 7 is driven by the rotational force of the driven roller 7b by a transmission means (not shown).

  A spur 7a is in pressure contact with the paper discharge roller 7. The printed recording paper P is sandwiched between the paper discharge roller 7b and the spur 7a, and is discharged and stored in the paper discharge tray 13. Since 7b rolls on the printing surface after recording, it has a shape in which the tip is sharpened so that the ink of the printed image is not transferred as much as possible.

Overall schematic diagram of a recording head of an embodiment of the present invention Schematic diagram of a recording element holding substrate of an embodiment of the present invention Schematic diagram of a partial sectional view of a recording head of an embodiment of the present invention Density distribution explanatory diagram of the embodiment of the present invention Partial schematic diagram of a recording element holding substrate of another embodiment of the present invention Explanation of concentration distribution at the chip boundary in the conventional example Overall schematic diagram of a conventional recording head It is the schematic of the full multi inkjet printer using the recording head of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Recording head 2 Head holder 4 Registration roller 5d Conveying belt 5a Driven roller 5c Pressure roller 5e Conveying belt housing 5b Driving roller 7 Paper discharge roller 8 Feeding roller 9 Manual feed 10 Cassette paper feed 12 Pinch roller 13 Paper discharge tray DESCRIPTION OF SYMBOLS 101 Recording element board | substrate 102 Discharge port 103 Flexible film 104 Recording element board | substrate holding member 105 Sealing material 106 Support member 107 Ink flow path 108 Ink supply port 120-123 Connection terminal 125-128, 134-136 Resistor 129-133,137 ~ 139 Conductor wiring

Claims (5)

  A plurality of chips are arranged in an inkjet recording head that forms a line head by arranging a plurality of recording element substrates each having a plurality of ejection energy generating elements for arranging kinetic energy to be applied to the ejection ports for ejecting the recording liquid. An ink recording head, wherein a heating heater is provided on a substrate to be printed.   2. The ink jet recording head according to claim 1, wherein a heater is provided around each chip.   2. The ink jet recording head according to claim 1, wherein a heater is provided between each chip.   2. An ink jet recording head according to claim 1, wherein each heater can be controlled independently.   An ink jet recording apparatus on which the ink jet head according to claim 1 is mounted.

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