JP2005074777A - Inkjet head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet head which can carry out good ink discharging by maintaining an ink temperature at a predetermined temperature. <P>SOLUTION: The inkjet head 4 has an inkjet head chip 41 with an ink discharge opening 42 at a leading end face 41a, a manifold 48 bonded and secured to a side part of the inkjet head chip for guiding ink to the inkjet head chip, and a housing frame 53 for storing the manifold. An ink heater 49 is provided between the manifold and the housing frame to heat the ink inside the manifold via the manifold. Moreover, an adhesive is filled between the manifold and the housing frame to include at least the ink heater. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an inkjet head, and more particularly to an inkjet head that discharges heated ink.

  2. Description of the Related Art Conventionally, ink jet printers that record predetermined images by ejecting ink onto recording media such as paper and plastic thin plates have been proposed and put into practical use. The ink jet printer includes an ink jet head having an ink ejection port, and ejects ink from the ink ejection port toward the recording medium while moving the ink jet head in a predetermined direction, thereby obtaining a predetermined image on the recording medium. It is recorded.

  In the ink jet printer, ink is ejected by an ink jet head using a piezoelectric element (piezo element) or the like. The ink-jet head includes an ink-jet head chip having an ink discharge port for discharging ink provided on a front end surface, a manifold that is bonded and fixed to a side portion of the ink-jet head chip and guides ink to the ink-jet head chip, and the manifold A housing frame for storing the housing.

By the way, since the viscosity of the ink used in the ink jet printer increases at low temperatures, it is necessary to heat the ink to reduce the viscosity and maintain the viscosity at a predetermined viscosity for the purpose of good ink ejection.
Therefore, conventionally, an ink heater is provided in an ink tank, or an ink heater (ink heating device) for heating a filter case of an inkjet head (nozzle head) is provided as described in Patent Document 1. .
JP-A-10-790

  However, in the ink heater provided in the ink tank as described above, the temperature of the ink may change before being ejected from the ink ejection port, and there is a possibility that good ink ejection cannot be performed. In addition, in the case of an ink heater that heats the filter case of the ink jet head, it is difficult to change the heating amount with respect to the temperature of the ink, thereby making it difficult to maintain the ink at a predetermined temperature and performing good ink ejection. Was the cause that can not.

  Accordingly, an object of the present invention is to provide an ink jet head that can perform good ink discharge by keeping the ink temperature at a predetermined temperature.

The invention described in claim 1
An ink jet head chip having an ink discharge port on the tip surface;
A manifold that is adhesively fixed to a side portion of the inkjet head chip and guides ink to the inkjet head chip;
A housing frame for housing the manifold;
An inkjet head comprising:
An ink heater is provided between the manifold and the housing frame to heat ink inside the manifold via the manifold, and an adhesive is provided between the manifold and the housing frame so as to include at least the ink heater. It is characterized by being filled.

The invention according to claim 2 is the ink jet head according to claim 1,
The ink heater is configured in a sheet shape.

The invention according to claim 3 is the inkjet head according to claim 1 or 2,
A sensor for detecting temperature is arranged closer to the inkjet head chip than the ink heater.

  According to the first aspect of the present invention, an ink jet head chip having an ink discharge port on the front end surface, a manifold that is bonded and fixed to a side portion of the ink jet head chip and guides ink to the ink jet head chip, and a housing that houses the manifold And an ink heater that heats ink inside the manifold via the manifold between the manifold and the housing frame, and includes at least an ink heater between the manifold and the housing frame. Thus, since the adhesive is filled, the ink can be heated quickly and appropriately, and the ink temperature can be maintained at a predetermined temperature. As a result, good ink discharge can be performed and good image formation can be performed.

  According to the invention described in claim 2, since the ink heater is formed in a sheet shape, the ink jet head can be formed in a compact manner.

  According to the third aspect of the present invention, since the sensor for detecting the temperature is arranged closer to the inkjet head chip than the ink heater, the ink temperature related to the ejection can be accurately measured. . In addition, since the temperature sensor is disposed close to the ink heater and the manifold, accurate temperature control can be performed.

  An embodiment of the present invention will be described below with reference to the drawings. However, the following is one embodiment of the present invention and does not limit the present invention.

  First, an overall configuration of an ink jet printer according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is an overall configuration diagram of an ink jet printer according to an embodiment of the present invention.

  The ink jet printer 1 ejects ink onto a recording medium P and records an image on the recording medium P. The ink jet printer 1 includes a transport unit (not shown), and the transport unit transports the recording medium P in the sub-scanning direction orthogonal to the main scanning direction A while passing through the recording area C in FIG. ing.

  Above the recording area C, a carriage rail 2 extending along the main scanning direction A is arranged. A carriage 3 guided by the carriage rail 2 is movably provided on the carriage rail 2. Yes.

  The carriage 3 is mounted with an inkjet head 4 that ejects ink onto the recording medium P, and moves in the direction of arrow A from the home position area B to the maintenance area D along the carriage rail 2.

  In the ink jet printer 1 according to the present embodiment, a total of four ink jet heads 4 are arranged in the carriage 3 so that four colors of ink of black (K), yellow (Y), magenta (M), and cyan (C) can be ejected. Is installed. In the present embodiment, two inkjet heads 4, 4 are arranged in a line in the front-rear direction, and the other two inkjet heads 4 are arranged on both sides of the center of the inkjet heads 4, 4 aligned in the front-rear direction. , 4 are arranged.

  Each of these inkjet heads 4 is connected to an ink tank 5 for storing black, yellow, magenta, and cyan inks via an ink supply pipe 6. That is, the ink in the ink tank 5 is supplied to each inkjet head 4 by the ink supply pipe 6.

  In the maintenance area D, a maintenance unit 7 that performs maintenance on the inkjet head 4 is provided. The maintenance unit 7 includes a plurality of suction caps 8 that cover the discharge surface 41a of the inkjet head 4 and suck ink in the nozzles, a cleaning blade 9 that wipes off ink adhering to the discharge surface 41a, and an inkjet head. An ink receiver 10 that receives ink ejected from 4, a suction pump 11, and a waste ink tank 12 are provided.

The suction cap 8 communicates with the waste ink tank 12 via the suction pump 11 and is raised during the maintenance operation so as to cover the ejection surface 41a of the inkjet head 4. Four suction caps 8, 8,... Are arranged so as to correspond to the respective ink-jet heads 4 so as to cover the ejection surfaces 41a of all the ink-jet heads 4 when raised as described above.
The suction pump 11 includes a cylinder pump and a tube pump, and operates in a state where the suction cap 8 covers the discharge surface 41a, thereby sucking ink in the inkjet head 4 together with foreign matter from the ink discharge port. For generating a suction force.

  In the home position area B, a moisturizing unit 13 for moisturizing the inkjet head 4 is provided. The moisturizing unit 13 is provided with four moisturizing caps 14 that moisturize the ink of the ink jet head 4 by covering the ejection surface 41a when the ink jet head 4 is in a standby state. These four moisturizing caps 14, 14,... Are arranged corresponding to the arrangement of the inkjet heads 4 so as to simultaneously cover the ejection surfaces 41a of the four inkjet heads 4.

  The control unit is configured to include a CPU (Central Processing Unit) and a memory, and controls each component of the inkjet printer 1. The memory stores image data to be formed on the recording medium P and a program for controlling each component of the inkjet printer 1, and controls each component based on the image data and program in the memory. A signal is transmitted.

Next, the inkjet head 4 according to the present invention will be described with reference to FIGS.
FIG. 2 is an exploded perspective view of the inkjet head 4 of the present embodiment, and FIG. 3 is a side view of the inkjet head 4 of the present embodiment. FIG. 4 is an enlarged perspective view of the vicinity of the inkjet head chip 41 and the manifold 48 of the inkjet head 4 of the present embodiment.

  The inkjet head 4 of the present embodiment is provided with an inkjet head chip (hereinafter referred to as “head chip”) 41 that ejects ink. The head chip 41 has a long outer shape, and a large number of ink discharge ports 42 are arranged on its discharge surface (tip surface) 41a. As shown in FIG. 3, ink supply ports 43 are provided on both side surfaces of the head chip 41, and the ink supply ports 43 and the ink discharge ports are connected via an ink flow path 44 formed inside the head chip 41. 42 is continuous. A part of the ink flow path 44 forms a pressure chamber, and has a structure in which an ink droplet is ejected from the ink ejection port 42 by changing the pressure by the action of a piezoelectric element (not shown).

  On both sides of the head chip 41, two sets of manifolds 48 that are connected to the ink supply port 43 and guide the ink from the outside to the head chip 41 are bonded and fixed. An inlet 481 through which ink flows is provided at one end of the manifold 48.

Further, an ink heater 49 is provided on the side of the manifold 48 between the manifold 48 and the housing frame 53 so as to contact the manifold 48 as shown in FIGS. The ink heater 49 is provided for heating the ink introduced into the manifold 48 to a predetermined temperature.
Further, an adhesive is filled between the manifold 48 and the housing frame 53 so as to include at least the ink heater 49, whereby the housing frame 53, the ink heater 49, and the manifold 49 are bonded and fixed. Yes.
Here, the manifold 49 is often made of resin, and the housing frame 53 is often made of metal or the like. Therefore, usually, a large amount of heat generated from the ink heater 49 is transmitted to the housing frame 53. In the present invention, the ink is filled between the ink heater 49 and the housing frame 53, so that the ink Heat conduction from the heater 49 to the housing frame 53 is suppressed, and heat generated from the ink heater 49 is appropriately transmitted to the ink inside the manifold 48 via the manifold 48.
Further, in the present embodiment, the ink heater 49 is configured in a sheet shape in which a heating wire 49a formed in a wave shape is disposed on an appropriate sheet.
In the example shown in FIGS. 3 and 4, the ink heater 49 is provided in contact with the manifold 48, but the ink heater 49 may be disposed away from the manifold 48.
The ink heater 49 may be installed on each of the two side portions of the manifold 48, or may be installed on only one of them.

The head chip 41 is connected to each of two sets of head drive substrates 46 that transmit a control signal from the control unit to each piezoelectric element via a flexible wiring board 47. A heater circuit for supplying power to the ink heater 49 is formed on the head drive substrate 46, and the heating wire 49 a of the ink heater 49 is electrically connected to the heater circuit via the electric wire 50. It is connected. Similarly, the temperature sensor 45 for detecting the temperature is electrically connected to the heater circuit by an electric wire (not shown). The temperature sensor 45 is disposed closer to the head chip 41 than the ink heater 49.
The two sets of head drive boards 46 are each provided with a connector 461, and each of these connectors 461 has an output terminal 62 of a flexible wiring board 60 having one input terminal 61 and two output terminals 62. It is connected. A power source and a control unit (not shown) are electrically connected to the input terminal 61 of the flexible wiring board 60, and a control signal and power are supplied to the head drive substrate 46 via the flexible wiring board 60. It is like that.

  A holding plate 51 for holding the manifold 48 and the head chip 41 is attached to the lower part of the head chip 41 so that the discharge surface 41a is exposed. At one end of the holding plate 51, an ink receiving portion 52 that holds the inlet 481 of the manifold 48 and allows ink to flow into the inlet 481 is formed.

As shown in FIG. 2, the inkjet head 4 is provided with the components of the inkjet head 4 such as the head chip 41, the manifold 48, the head drive substrate 46, and the holding plate 51. A frame 53 and a cover 54 that covers the housing frame 53 are provided. The casing frame 53 is provided with a frame ink flow path 55 that supplies ink by being connected to the ink receiving portion 52 of the holding plate 51, and the ink supply pipe 6 is connected to the frame ink flow path 55. It has come to be. In addition, support beams 56 that support two sets of head drive substrates 46 are provided inside the housing frame 53.
An opening 57 is provided in the upper part of the cover 54, and the input terminal 61 of the flexible wiring board 60 is exposed to the outside from the opening 57 after the ink jet head 4 is assembled.

Next, the operation of this embodiment will be described.
When the power of the ink jet printer 1 is turned on, power is supplied to each part of the ink jet printer 1. Accordingly, when power is supplied to the ink heater 49, the heating wire 49a of the ink heater 49 generates heat, and the ink in the manifold 48 is heated via the manifold 48 to reduce the viscosity.
Thereafter, when an instruction to start image recording is input, the control unit transmits a control signal based on the image data to the head driving substrate 46 and other driving units to start image recording. Ink is ejected from the inkjet head 4 onto the recording medium P that is transported to the transporting means. When this ink is ejected, the ink is preheated to reduce the viscosity, so that stable ejection and high image quality are achieved. An image is formed.

  As described above, according to the ink jet head in the present embodiment, the ink jet head chip having the ink discharge port on the front end surface, the manifold that is bonded and fixed to the side portion of the ink jet head chip and guides the ink to the ink jet head chip, and the manifold An ink jet head including an ink heater that heats ink inside the manifold via the manifold between the manifold and the housing frame, and between the manifold and the housing frame, Since the adhesive is filled so as to include at least the ink heater, the ink can be heated quickly and appropriately, and the ink temperature can be maintained at a predetermined temperature. As a result, good ink discharge can be performed and good image formation can be performed.

  Further, in the present embodiment, since the ink heater is configured in a sheet shape, the ink jet head can be formed in a compact manner.

  Furthermore, in the present embodiment, since the sensor for detecting the temperature is arranged closer to the inkjet head chip than the ink heater, the ink temperature related to the ejection can be accurately measured. In addition, since the temperature sensor is disposed close to the ink heater and the manifold, accurate temperature control can be performed.

  The ink jet head and the ink jet printer according to the present invention are not limited to the above-described embodiments, and can be applied to other configurations. For example, the ink jet head is not limited to a configuration including a piezoelectric element in a head chip, and may be configured to include a heater, for example.

1 is a plan view illustrating an outline of an inkjet printer according to an embodiment of the present invention. 1 is an exploded perspective view of an inkjet head according to an embodiment of the present invention. It is a side view of the ink jet head concerning one embodiment of the present invention. FIG. 2 is an enlarged perspective view of the vicinity of a head chip and a manifold of an inkjet head according to an embodiment of the present invention.

Explanation of symbols

1 Inkjet printer 4 Inkjet head 41 Head chip (inkjet head chip)
41a Discharge surface (tip surface)
42 Ink Ejection Port 45 Temperature Sensor 48 Manifold 49 Ink Heater 49a Heating Wire 53 Housing Frame P Recording Medium

Claims (3)

An ink jet head chip having an ink discharge port on the tip surface;
A manifold that is adhesively fixed to a side portion of the inkjet head chip and guides ink to the inkjet head chip;
A housing frame for housing the manifold;
An inkjet head comprising:
An ink heater is provided between the manifold and the housing frame to heat ink inside the manifold via the manifold, and an adhesive is provided between the manifold and the housing frame so as to include at least the ink heater. An ink jet head which is filled. The inkjet head according to claim 1,
An ink jet head, wherein the ink heater is formed in a sheet shape. The inkjet head according to claim 1 or 2,
An ink jet head, wherein a sensor for detecting temperature is disposed closer to the ink jet head chip than the ink heater.

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