JP2009172852A - Inkjet head and inkjet recording apparatus carrying inkjet head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet head capable of suppressing to transmit heat which a controlling substrate generates in the head chip even though it has a simple constitution. <P>SOLUTION: The inkjet head 2 includes a controlling base 15, a head chip unit 10 having the head chip 11 for jetting ink toward a recording medium from an ink jetting hole 14a by a signal from the controlling base, and a supporting base 20 having a first fixing part 20a for fixing the head chip and a second fixing part 20b for fixing the controlling base. In the supporting base, an intermediate part positioned between the first fixing part and the second fixing part includes a heat transmission suppressing part 20e for suppressing to transmit heat from the second fixing part to the first fixing part. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an inkjet head of an inkjet recording apparatus that prints by ejecting ink.

An inkjet head of a conventional inkjet recording apparatus includes a first support base that fixes a circuit board (control board) having a drive IC, and a second support base that fixes a head chip controlled by a signal from the drive IC. (For example, refer to Patent Document 1).
Then, connecting portions offset to the back side are provided at both ends of one side of the first support base, and the second support base is made of a heat insulating material so that the surface of the first support base and the surface of the second support base are substantially flush with each other. It was fixed to the connection part of the 1st support base via.
The reason for fixing the first support base and the second support base via the heat insulating material is to suppress the heat generated by the drive IC from being transmitted to the head chip via the first support base and the second support base. . If the temperature of the head chip becomes too high, there is a risk that ejection failure such as missing dots where ink is not ejected from the ink ejection holes for ejecting ink, or deflection where the direction in which ink is ejected deviates will occur.
In addition, the reason why the surface of the first support base and the surface of the second support base are fixed so as to be substantially flush is to arrange the circuit board and the head chip compactly on substantially the same face.
JP 2001-232788 A

  However, in the conventional ink jet recording apparatus shown in Patent Document 1, it is necessary to provide connection portions offset on the back side at both ends of one side of the first support base, and two supports, a first support base and a second support base. Since the base is required, the configuration of the inkjet head is complicated as a whole.

  The present invention has been made in view of such problems, and is equipped with an inkjet head and an inkjet head that can suppress the heat generated by the control board from being transmitted to the head chip with a simple configuration. An inkjet recording apparatus is provided.

In order to solve the above problems, the present invention proposes the following means.
The inkjet head of the present invention includes a control substrate, a head chip unit having a head chip that ejects ink from an ink ejection hole toward a recording medium by a signal from the control substrate, and a first fixing portion that fixes the head chip. And a support base having a second fixing part for fixing the control board, and an intermediate position between the first fixing part and the second fixing part in the support base The portion is provided with a heat transfer suppressing portion that suppresses heat from the second fixing portion from being transferred to the first fixing portion.

  According to this invention, the head chip is fixed to the first fixing portion of the support base, and the control board is fixed to the second fixing portion of the support base. In the support base, heat transfer that suppresses the heat generated by the control board fixed to the second fixing portion from being transmitted to the first fixing portion is provided in an intermediate portion located between the first fixing portion and the second fixing portion. A suppression unit is provided. Therefore, it is possible to suppress the heat generated by the control board from being transmitted to the head chip with a simple configuration in which the heat transfer suppressing portion is provided on the support base.

Further, the heat transfer suppression portion corresponds to the ink ejection holes arranged in the head chip at intervals in one direction along the surface of the support base in the intermediate portion of the support base. More preferably, the through hole extends continuously in the one direction.
According to the present invention, the transfer of heat from the second fixed portion side to the first fixed portion side of the portion corresponding to the many ink ejection holes arranged can be suppressed. For this reason, it is possible to effectively suppress the heat generated by the control board from being transmitted to the ink in the ink ejection holes.

Further, the heat generated by the control board passes through a part of the support base located on both sides of the through hole, and is transmitted to the ink ejection holes located at both ends of the ink ejection holes arranged on the head chip.
Of the many ink ejection holes that are generally arranged, the ink is ejected from the ink ejection holes located at both ends, particularly because the heat of the ink in the ink ejection holes located at both ends is transmitted to the carriage and taken away. There is a tendency for the temperature of the ink to be reduced.
As the ink temperature decreases, the viscosity of the ink increases, so even if the control board issues a command to simultaneously eject ink to a plurality of ink ejection holes arranged in one direction, the ink is ejected from the ink ejection holes. The time required for the ink to reach the recording medium becomes longer as the temperature of the ink is lower. For this reason, when a large number of ink ejection holes arranged in one direction are scanned in a direction perpendicular to the one direction, the recording medium is fixed by causing the control substrate to eject ink simultaneously from the ink ejection holes. Even when trying to draw a straight line, there is a problem that the line actually printed on the recording medium is bent.
According to the present invention, the through holes extending continuously in the one direction described above are provided in the portions corresponding to the many ink ejection holes arranged at both ends of the ink ejection holes arranged in one direction of the head chip. The temperature of the ink in the ink ejection holes of the part can be increased, and the temperature of the ink in the ink ejection holes arranged in a number of directions can be made uniform.

More preferably, a heat insulating material is disposed in the through hole.
According to the present invention, it is possible to more effectively suppress the heat generated by the control board from being transmitted to the head chip unit.

Further, it is more preferable to provide a heating means for heating the ink ejection holes located at both ends of the ink ejection holes arranged in the one direction among the many ink ejection holes arranged.
According to the present invention, even when the heat generated by the control board decreases, the vicinity of both ends of the head chip unit can be heated by the heating means. Accordingly, it is possible to suppress the temperature drop of the ink in the ink ejection holes at both ends of the ink ejection holes arranged in many directions and make the temperature of the ink in each ink ejection hole more uniform.

Moreover, it is more preferable that the ink jet recording apparatus of the present invention is equipped with the ink jet head described above.
According to the present invention, in the support base provided in the ink jet head of the ink jet recording apparatus, the heat transfer suppressing portion is provided between the first fixing portion for fixing the head chip unit and the second fixing portion for fixing the control substrate. . Therefore, it is possible to suppress the heat generated by the circuit board from being transmitted to the head chip unit with a simple configuration in which the heat transfer suppressing portion is provided on the support base.

  According to the ink jet head and the ink jet recording apparatus equipped with the ink jet head of the present invention, the heat generated by the control board can be suppressed from being transmitted to the head chip unit with a simple configuration.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 1 to 5 are explanatory views of the ink jet recording apparatus according to the first embodiment of the present invention. 1 is a perspective view of the whole, and FIG. 2 is a perspective view of a main part in FIG.
In the present embodiment, an ink jet printer will be described as an example of an ink jet recording apparatus.

As shown in FIGS. 1 and 2, the inkjet printer 1 of the present embodiment conveys a plurality of inkjet heads 2 that eject ink W of different colors and a recording sheet P in a predetermined conveyance direction L <b> 1. A transport unit 3 and a moving unit 4 that reciprocally moves a head chip 10 (to be described later) of the inkjet head 2 in an orthogonal direction L2 orthogonal to the transport direction L1 are provided. The head chip 10 is moved in the direction L2, and characters, figures, and the like are recorded on the recording paper P.
Note that the recording paper P corresponds to the recording medium of the claims, and may be a cut paper, a continuous paper, a slip, or the like.
Further, in the illustrated example, four inkjet heads 2 are provided and black, cyan, magenta, and yellow ink W is ejected as an example. These four inkjet heads 2 have the same configuration.

The four inkjet heads 2 are fixed to the carriage 32 with fixing screws 39 in a state of being arranged in the orthogonal direction L2 to the carriage 32. A supply tube 31 that supplies ink W from the ink tank 33 is connected to each inkjet head 2.
The carriage 32 is disposed on a pair of guide rails 34 extending on the base 30 along the orthogonal direction L2 so as to be movable in the orthogonal direction L2, and is disposed at an interval in the orthogonal direction L2. A conveyor belt 36 wound around a pair of pulleys 35 is connected.
Of the pair of pulleys 35, one pulley 35 is rotated by receiving a rotational driving force from a drive motor 37 fixed to the base 30.
Thus, the carriage 32 can reciprocate along the orthogonal direction L2. That is, the pair of guide rails 34, the pair of pulleys 35, the transport belt 36, and the drive motor 37 constitute the moving unit 4.

The base 30 is provided with two pairs of transport rollers 38 whose axes are extended in the orthogonal direction L2 at intervals in the transport direction L1. A pair of guide rails 34 is disposed between these two sets of transport rollers 38. The pair of transport rollers 38 are arranged such that their respective axes are spaced from each other in a direction orthogonal to both the transport direction L1 and the orthogonal direction L2, and the recording paper is interposed between the pair of transport rollers 38. P is sandwiched.
The pair of transport rollers 38 are supported by motors (not shown) so as to rotate in opposite directions around the respective axes, and the recording paper P sandwiched between the transport rollers 38 is transported in the transport direction L1. It is designed to be transported. That is, the pair of transport rollers 38 constitutes the transport unit 3.

Here, FIG. 3 shows an exploded perspective view of the inkjet head 2.
As shown in FIGS. 2 and 3, the inkjet head 2 includes a head chip 11 that ejects ink W, a support base 20, an ink flow path member 21, and a damper 22. The head chip unit 10 includes a control substrate 15, a head chip 11 that ejects ink W toward the recording paper P in response to a signal from the control substrate 15, and a nozzle cap 16 that fixes the head chip unit 10 to the support base 20. And a flexible printed wiring (FPC) 17 that electrically connects the control board 15 and the head chip unit 10.
The support base 20 is formed of an aluminum alloy as a material by a casting method, and includes a head chip fixing portion 20 a that fixes the head chip 11 via the nozzle cap 16 and a substrate fixing portion 20 b that fixes the control substrate 15.
The chip fixing part 20a corresponds to the first fixing part in the claims, and the substrate fixing part 20b corresponds to the second fixing part.

The damper 22 is disposed between the supply tube 31 that supplies the ink W to the inkjet head 2 and the ink flow path member 21, and relieves inertial force generated by the movement of the head chip 11. And it is fixed to the support base 20 by the base 22a formed in the damper 22, and is supported by the bearing part 20f provided in the support base 20. FIG.
Further, the ink flow path member 21 is injection-molded with a synthetic resin, and a pair of left and right flange portions 21 a fixed to the first screw hole 20 c formed in the support base 20 by the first set screw 23 is formed. Further, the ink flow path member 21 is formed with a connection portion 21 b to which the damper 22 is connected, and guides the ink W supplied from the damper 22 to the head chip 11.

The head chip 11 has a groove portion (not shown) formed therein, an actuator plate 12 that generates a driving force for ejecting the ink W through the groove portion, a cover plate 13 that covers a part of the groove portion of the actuator plate 12, and an ink that ejects the ink W. And a nozzle rate 14 in which many injection holes 14a are arranged. A large number of ink ejection holes 14 a arranged in the nozzle rate 14 are arranged at intervals in one direction L3 along the surface 20 g of the support base 20.
Note that when the head chip 11 having the nozzle rate 14 is fixed to the ink jet printer 1, the one direction L3 coincides with the transport direction L1.
Further, the flexible printed wiring 17 is fixed to the second screw hole 20 d formed in the support base 20 together with the control board 15 by the second set screw 24.
A driving IC 15 a is mounted on the control board 15 and drives the head chip 11.

Further, in the support base 20, a through hole 20e is formed at an intermediate portion located between the head chip fixing portion 20a and the substrate fixing portion 20b. The through-hole 20e extends continuously in one direction L3 at a portion corresponding to a large number of arranged ink ejection holes 14a.
Here, in order to explain in detail, FIG. 4 shows an arrow view seen from the X direction perpendicular to the surface 20g of the support base 20 by connecting related parts of the inkjet head 2 shown in FIG. As shown in FIG. 4, the axes of the ink ejection holes 14a located at both ends of the many ink ejection holes 14a correspond to the positions of both ends of the through hole 20e, and are located at both ends. Both the width of the ink ejection holes 14a and the width of the through holes 20e are a predetermined length H.
The through hole 20e is filled with a heat insulating material 40 which is a synthetic resin having high heat insulating properties.
And as shown in FIG. 5, the heater 41 which is a heating means which heats the ink ejection hole 14a located in the both ends mentioned above is affixed on position A1.

  Thus, according to the inkjet printer 1 of the first embodiment of the present invention, the head chip 11 is fixed to the head chip fixing part 20a of the support base 20, and the control board 15 is fixed to the board fixing part 20b of the support base 20. . In the support base 20, heat generated by the control substrate 15 fixed to the substrate fixing portion 20b is transmitted to the head chip fixing portion 20a at an intermediate portion located between the head chip fixing portion 20a and the substrate fixing portion 20b. A through-hole 20e is provided to suppress the above. The through hole 20e suppresses the heat transmitted to the substrate fixing part 20b from being transmitted to the head chip fixing part 20a, so that the heat generated by the control board 15 is transmitted to the head chip 11 to the support base 20 through the through hole. It can be suppressed with a simple configuration in which only 20e is provided.

Further, the through hole 20e has a shape that continuously extends over a predetermined length H in one direction L3 to a portion corresponding to the many ink ejection holes 14a arranged in the intermediate portion of the support base 20. For this reason, the heat transfer from the substrate fixing part 20b side to the head chip fixing part 20a side in the portion corresponding to the many ink ejection holes 14a is suppressed, and the heat generated by the control board 15 is generated in the ink ejection holes 14a. Transmission to the ink W can be effectively suppressed.
Further, when the air temperature in the environment where the ink jet printer 1 is used is high, the temperature of the ink W in the ink ejection holes 14a particularly increases, and the occurrence rate of ejection defects such as missing dots and deflection becomes high. . Even in such a case, the through hole 20e having a predetermined length H corresponding to the width of the predetermined length H in which the ink ejection holes 14a are arranged is formed in the support base 20 as in the present embodiment. Thus, the heat transmitted from the control board 15 to the ink ejection holes 14a can be effectively suppressed.
Moreover, the heat insulating material 40 is filled in the through hole 20e. Therefore, the heat transmitted from the control board 15 to the ink ejection holes 14a can be more effectively suppressed.

Further, as shown in FIG. 4, the heat generated by the control board 15 passes through the connection portions 20h that are part of the support base 20 located on both sides of the through hole 20e, and a large number of ink ejection holes 14a arranged in the head chip 11. Is transmitted to the ink ejection holes 14a located at both ends of the ink.
Among the ink ejection holes 14a that are generally arranged in large numbers, the inks located at both ends particularly due to the heat of the ink W in the ink ejection holes 14a located at both ends being transmitted to the carriage 32 and taken away. There is a tendency that the temperature of the ink W ejected from the ejection holes 14a decreases.
As the ink temperature decreases, the viscosity of the ink increases, so even if the control board issues a command to simultaneously eject ink to a plurality of ink ejection holes arranged in one direction, the ink is ejected from the ink ejection holes. The time required for the ink to reach the recording paper becomes longer as the temperature of the ink is lower. For this reason, when a large number of ink ejection holes arranged in the transport direction are scanned in a direction orthogonal to the transport direction, the control substrate is fixed by ejecting ink simultaneously from the ink ejection holes a. Even when trying to draw a straight line, the line actually printed on the recording paper is bent.
In this embodiment, by providing the pair of heaters 41 that heat the ink ejection holes 14a located at both ends described above, the temperature drop of the ink W in the ink ejection holes 14a located at both ends is suppressed, and each ink ejection is performed. The temperature of the ink W in the hole 14a can be made more uniform.

In the above embodiment, the head chip 11 is fixed to the first fixing portion via the nozzle cap 16. However, the head chip 11 may be directly fixed to the first fixing portion.
Moreover, in the said embodiment, although the heat-transfer suppression part provided in the support base 20 was made into the through-hole 20e, chip | tip fixation from the board | substrate fixing | fixed part 20b side is made thin by making the thickness of the heat-transfer suppression part of the support base 20 thin. You may make it the structure which suppresses transmission of the heat | fever to the part 20a side.

Moreover, in the said embodiment, the heat insulating material 40 was filled in the through-hole 20e. However, the heat insulating material 40 does not need to be packed in the through hole 20e without a gap, and may be configured such that the heat insulating material 40 is attached to the wall surface that forms the through hole 20e.
Furthermore, you may make it the structure by which the heat insulating material 40 is not distribute | arranged in the through-hole 20e.

In the above embodiment, as shown in FIG. 5, the heater 41 is attached to the position A <b> 1 of the support base 20 in order to heat the ink ejection holes 14 a located at both ends. However, the position where the heater 41 is pasted may be the position A2 on the surface 20g of the support base 20, or the position A3 that hits the back of the position A2 with respect to the support base 20.
In the above embodiment, the heater 41 is attached to heat the ink ejection holes 14a located at both ends. However, the heater 41 may not be arranged. This is because the temperature of the ink W in each ink ejection hole 14a can be made more uniform simply by providing the through hole 20e depending on conditions such as the outside air temperature.

1 is a perspective view of an inkjet printer according to an embodiment of the present invention. It is the principal part perspective view which fractured | ruptured some ink jet printers of embodiment of this invention. 1 is an exploded perspective view of an inkjet head of an inkjet printer according to an embodiment of the present invention. FIG. 4 is a view taken in the direction of the arrow X in FIG. 3 in a state where main components of the ink jet head according to the embodiment of the present invention are combined. It is explanatory drawing which showed the position which affixes a heater on the support base of embodiment of this invention.

Explanation of symbols

1 Inkjet printer (inkjet recording device)
2 Inkjet head 10 Head chip unit 11 Head chip 14a Ink ejection hole 15 Control substrate 20 Support base 20a Head chip fixing part (first fixing part)
20b Substrate fixing part (second fixing part)
20e Through hole (heat transfer suppression part)
40 Heat insulation material 41 Heater (heating means)
L3 Unidirectional P Recording paper (recording medium)
W ink

Claims (5)

A control board;
A head chip unit having a head chip that ejects ink from the ink ejection holes toward the recording medium by a signal from the control board;
An ink-jet head comprising: a first fixing portion for fixing the head chip; and a support base having a second fixing portion for fixing the control substrate.
In the support base, a heat transfer suppressing portion that suppresses heat from the second fixing portion from being transmitted to the first fixing portion at an intermediate portion located between the first fixing portion and the second fixing portion. An ink jet head comprising: The inkjet head according to claim 1,
The heat transfer suppression portion is formed in a portion corresponding to the ink ejection holes arranged in the head chip at intervals in one direction along the surface of the support base in the intermediate portion of the support base. An ink-jet head characterized by being a through-hole extending continuously in one direction. The inkjet head according to claim 2,
An ink-jet head, wherein a heat insulating material is disposed in the through hole. In the ink jet head according to claim 2 or 3,
An ink-jet head comprising heating means for heating the ink ejection holes positioned at both ends of the ink ejection holes arranged in one direction among the plurality of ink ejection holes arranged.   An ink jet recording apparatus comprising the ink jet head according to claim 1.

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