JP2017200740A - Liquid discharge unit and liquid discharge device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable curing of UV ink mist included in a suction air flow generated by a fan and thus reduce effects on an amplifier substrate and the like.SOLUTION: A liquid discharge unit/liquid discharge device includes: a liquid discharge head for discharging liquid including light curable resin curing through light irradiation; a circuit board electrically connected to the liquid discharge head; a first light irradiation device for irradiating the discharged liquid with light; a fan for sending air to the circuit board; and a second light irradiation device for irradiating a suction air flow generated by the fan with light on the upstream side of the fan. Since the second light irradiation device enables curing of UV ink mist included in the suction air flow generated by the fan, effects on an amplifier substrates and the like can be reduced.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a liquid discharge unit and a liquid discharge apparatus. The liquid discharge unit is an assembly of functional parts and mechanisms integrated with a liquid discharge head that discharges liquid from a nozzle, and is an assembly of parts related to liquid discharge. The liquid discharge apparatus is an apparatus that includes a liquid discharge unit and drives a liquid discharge head to discharge liquid.

  A circuit that drives a liquid discharge head (for example, an inkjet head) that discharges liquid from a nozzle includes a circuit board such as an amplifier that generates and amplifies a head drive signal for liquid discharge. Since such a circuit board generates heat when in use, a technique for air-cooling the circuit board by providing air blowing means in which dust or the like is reduced by a filter is used as means for cooling the heat generating portion.

  For example, Patent Document 1 discloses a cooling device that cools a heat generating device that generates heat as the process is executed. In this cooling device, the temperature of the heat generating portion of the heat generating device is monitored by a temperature detector, and the presence / absence of the clogging of the dustproof filter is determined. Therefore, it is possible to appropriately grasp the filter replacement time.

  However, in the conventional technique of removing dust and the like using a filter, the filter must be rough to some extent in order to obtain a predetermined amount of cooling air, and fine particles such as uncured UV ink mist are filtered. Pass a lot. Further, the UV ink mist often contains a solvent component and the like, and there has been a problem that a circuit board connected to the liquid ejection head fails due to the solvent component.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a liquid discharge unit / liquid discharge capable of curing a mist (for example, UV ink mist) containing a photocurable resin contained in an intake flow generated by a fan and reducing an influence on a circuit board or the like. Is to provide a device.

The above-described problem is directed to a liquid discharge head that discharges a liquid containing a photocurable resin that is cured by light irradiation, a circuit board that is electrically connected to the liquid discharge head, and the discharged liquid. A first light irradiation device for irradiating light, a fan for blowing air to the circuit board,
The liquid discharge unit includes: a second light irradiation device that irradiates the intake air flow generated by the fan with light upstream of the fan.

  In addition, the above-described problems may be caused by a liquid discharge head that discharges a liquid containing a photocurable resin that is cured by light irradiation, a circuit board that is electrically connected to the liquid discharge head, and the discharged liquid. A first light irradiating device that irradiates light, a fan that blows air to the circuit board, a second light irradiating device that irradiates light on the upstream side of the fan into the intake air flow generated by the fan, And a liquid discharge apparatus that drives the liquid discharge head to discharge the liquid.

  Since the liquid discharge unit / liquid discharge apparatus of the present invention includes the second light irradiation device that irradiates light to the intake air flow generated by the fan, the UV ink mist contained in the intake air flow is cured and applied to a circuit board or the like. The impact can be reduced.

1 is a perspective view of a UV-IJ (inkjet) printing apparatus that is a liquid ejection apparatus according to an embodiment of the present invention. It is a front view of the apparatus shown in FIG. It is a perspective view which shows the conventional liquid discharge unit. It is a schematic diagram which shows the cross section of the liquid discharge unit shown in FIG. It is a schematic diagram which shows the cross section of the liquid discharge unit which concerns on 1st Embodiment. It is a schematic diagram which shows the cross section of the liquid discharge unit which concerns on 2nd Embodiment. It is a schematic diagram which shows the cross section of the liquid discharge unit which concerns on 3rd Embodiment. It is a schematic diagram which shows the cross section of the liquid discharge unit which concerns on 4th Embodiment.

(First embodiment)
FIG. 1 is a perspective view of a UV-IJ (inkjet) printing apparatus which is a liquid ejection apparatus according to an embodiment of the present invention, and FIG. 2 is a front view of the apparatus.

  The carriage 15 attached on the linear actuator 10 is moved along the X-axis direction by the linear actuator 10. The carriage 15 is provided with a linear actuator that can move in the Z-axis direction. The carriage 15 can move in the Z-axis direction. The carriage 15 includes a plurality of inkjet heads 16 that are liquid ejection heads, and a surface (nozzle surface) on which nozzles that are liquid ejection ports are formed is opposed to the recording medium P. Each inkjet head 16 is UV-cured for each color including colored components (pigments or dyes) of yellow (Y), cyan (C), magenta (M), and black (K) (photocuring that is cured by light such as ultraviolet rays). Ink containing mold resin). Each inkjet head 16 forms an image on the recording medium P by ejecting UV ink onto the recording medium P in synchronization with the movement of the carriage 15 in the X-axis direction.

  At both ends of the carriage 15 in the X-axis direction, UV lamps 17a and 17b (ultraviolet irradiation devices) for curing ink landed on the recording medium P are provided. In FIG. 1, the UV irradiation light 24 from the right UV lamp 17a is drawn as an image. In addition to such a diffused light type, various light irradiation devices such as a condensing type UV lamp can be used according to the purpose.

  The liquid ejection device shown in FIGS. 1 and 2 assumes that the carriage 15 performs printing while moving from right to left (negative direction of the X axis). Since the carriage 15 moves to the left, the ink ejected from the head 16 is cured by receiving light from the right UV lamp 17a after landing on the recording medium P. On the other hand, when performing printing while moving in the reverse direction by bidirectional printing, the ink is cured by receiving light from the left UV lamp 17b after landing on the recording medium P. If the UV ink has poor curability and the cumulative amount of UV light necessary for curing is large, both the left and right UV lamps 17a and 17b may be irradiated and cured after printing.

  Ink supply to each head 16 is performed by sending ink from a main ink tank provided in the apparatus base 18 to a sub tank provided in the carriage 15. At this time, a supply pump provided in the apparatus base 18 is used. The supply pump is connected to the sub tank, and the sub tank is connected to the head by ink supply tubes. The inside of the sub tank is maintained at a minute negative pressure suitable for ink discharge by an air pipe, a solenoid valve, an air negative pressure generating pump and a controller for controlling them.

  The air piping is also connected to an air pressurizing pressure source via a solenoid valve. This is because, for example, when dust or bubbles adhere to the nozzles and normal ink ejection cannot be performed, the ink is forcibly discharged from the nozzles of the head 16 by switching the sub tank from negative pressure to positive pressure. Used to flush away air bubbles. When discharging the ink, the head 16 is moved onto the waste liquid receiver 19 and the nozzle surface is wiped (wiping) using a wiper 21 provided in the waste liquid receiver 19 and movable in the Y-axis direction. To do. Note that the wiper 21 is generally provided with elasticity such as rubber or elastomer. The ink discharged from the nozzles or the ink wiped off by wiping is collected in a waste liquid tank provided in the apparatus base 18 via a waste liquid receiver 19.

  The linear stage 22 provided on the apparatus base 18 holds the recording medium P and conveys it in the Y-axis direction. Further, the linear stage 22 faces the nozzle surface of the head 16. The moving direction of the linear stage 22 shown in FIGS. 1 and 2 is only in the Y-axis direction, but a stage having a θ correction function that rotates around the Z-axis, and a stage that can rotate around the Y-axis and the X-axis are used. Thus, it can be applied to recording media of various shapes.

  The surface of the linear stage 22 has fine holes at regular intervals. By performing suction from the back surface of the stage 22 using a vacuum pressure generation source such as a vacuum pump, a negative pressure is generated in the hole, and a thin recording medium P such as a film placed on the stage 22 can be adsorbed to the stage 22.

  As the recording medium P on which images and characters are recorded on the surface, a sheet having a thickness such as a plate material (wood, metal, resin) can be used in addition to the sheet-like film. When recording media having different thicknesses are used, an appropriate distance between the recording medium P, the head 16 and the UV lamp 17 can be maintained by moving the carriage 15 in the Z-axis direction.

  The empty discharge receptacle 26 provided on the side of the linear stage 22 is used to discard (empty discharge) ink that has deteriorated due to contact with air for a long time (so-called “discarding”). As a result, fresh ink can be supplied to the nozzles to maintain print quality. Note that the idle ejection is preferably performed at the start of printing or during printing. A cap 28 is provided next to the idle discharge receiver 26. The cap 28 is used to cover the head 16 after the apparatus is used or when it is not used for a long period of time, and protects the nozzle surface and ink near the nozzle surface.

  Subsequently, in order to facilitate understanding of the features of the present invention, the configuration of a conventional liquid discharge unit will be described.

  FIG. 3 is a perspective view showing a conventional liquid discharge unit. The liquid discharge unit includes a carriage 15 that reciprocates along a guide rod 23, a plurality of inkjet heads 16, an amplifier substrate 20 that is one of circuit boards electrically connected to each inkjet head 16, and a UV lamp 17. Etc.

  Each inkjet head 16 includes, for example, a piezoelectric actuator (laminated piezoelectric element or thin film piezoelectric element) as an energy generation source for ejecting ink. Alternatively, a thermal actuator using an electrothermal conversion element such as a heating resistor, an electrostatic actuator composed of a diaphragm and a counter electrode, or the like can be used. Each inkjet head 16 is supplied with UV ink through an ink supply mechanism.

  Each amplifier substrate 20 applies a drive signal to the inkjet head 16 based on a signal from a controller in the liquid ejection apparatus. Specifically, the amplifier substrate 20 sends a drive signal to the ink jet head 16 in synchronization with the movement of the carriage 15, so that the ink jet head 16 ejects ink at an appropriate timing and landes the ink on the recording medium P. . The UV ink that has landed on the recording medium P is cured by the UV light emitted from the UV lamp 17.

  When the amplifier substrate 20 generates a drive signal, it generates heat to amplify the signal to a level necessary for driving the head. As a cooling means for the amplifier board 20, the carriage 15 is provided with an intake fan 30 and a filter 31 attached to the intake side of the intake fan 30. Cooling is performed by sucking outside air by the intake fan 30 and blowing it to each amplifier board 20 (air blowing). In addition, dust and the like included in the intake air flow are removed by the filter 31. Note that a heat sink may be provided on each amplifier board 20 to further enhance the cooling effect.

  4 is a schematic diagram showing a cross section of the liquid ejection unit shown in FIG. As shown in FIG. 4, all the ink droplets ejected from the inkjet head 16 ideally land on the recording medium P facing the nozzle surface of the inkjet head 16. In practice, however, minute ink droplets called ink mist are often generated due to various factors such as the ink composition, the state of the head 16, the ambient temperature, and the shape of the drive signal (drive waveform).

  Since the ink mist has a small mass, the ink mist is easily affected by air resistance and airflow generated by the movement of the carriage 15. Some ink mists float in the air without landing on the recording medium P. Some of these ink mists are sucked by an intake fan 30 that cools the amplifier board 20 (arrow F in the figure) and sprayed onto the amplifier board 20.

  As described above, the filter 31 is provided on the suction side of the intake fan 30 so that dust and dust larger than a certain size can be removed. However, the ink mist is small in size and passes except for a part. In addition, since the ink mist is in a liquid state before being cured, it is likely to adhere when it comes into contact with an object, and is difficult to fall once attached. Since the surface of the amplifier board 20 (and the heat sink) is covered with the UV ink, the cooling efficiency of the amplifier board 20 (and the heat sink) is lowered. Further, the UV ink may contain a solvent component that erodes the amplifier substrate 20 (and components on the substrate), which causes a problem that the substrate deteriorates or breaks down.

  Hereinafter, characteristic portions of the present invention will be described.

  FIG. 5 is a schematic view showing a cross section of the liquid ejection unit according to the present embodiment. 5, the same components as those in FIG. 4 are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 5, the liquid ejection unit includes a UV lamp 32 that is a light irradiation device on the upstream side of the filter 31. Here, the UV lamp 17 for curing the ink on the recording medium P is called a first light irradiation device, and the UV lamp 32 for irradiating light to the intake air flow generated by the intake fan 30 is the second light irradiation device. Call it.

  With such a configuration, the UV ink mist being sucked by the intake fan 30 is irradiated with light by the UV lamp 32, so that it is in a cured state, that is, a state close to a resin powder. Compared to liquid ink mist, even when it comes into contact with an object, it is less likely to adhere, and a reduction in cooling efficiency can be prevented. In addition, since components such as a solvent that erodes the amplifier substrate 20 (and components on the substrate) due to the curing reaction of the UV ink are eliminated, deterioration and failure of the amplifier substrate 20 can be reduced.

(Second Embodiment)
FIG. 6 is a schematic diagram illustrating a cross section of the liquid ejection unit according to the second embodiment. 6, the same components as those in FIG. 5 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The liquid discharge unit according to the present embodiment further includes a duct 33a through which an intake air flows on the upstream side of the filter 31, and irradiates light inside the duct for curing the UV ink mist from the UV lamp 32. Thereby, light can be irradiated to all of the intake air flow (that is, ink mist), and the UV ink mist in the intake air flow can be cured.

(Third embodiment)
FIG. 7 is a schematic diagram illustrating a cross section of the liquid ejection unit according to the third embodiment. 7, the same components as those in FIG. 6 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The liquid discharge unit of this embodiment includes a duct 33b formed of a material that does not transmit light from the UV lamp 32 (for example, a metal material, a black resin, or the like). In some cases, parts that are easily deteriorated by light (such as ultraviolet rays) from a UV lamp may be used in the liquid ejection apparatus main body and its peripheral devices. By preventing leakage of UV light irradiated by the UV lamp 32 to the outside of the duct 33b, it is possible to prevent deterioration of components that are vulnerable to ultraviolet rays.

(Fourth embodiment)
FIG. 8 is a schematic diagram illustrating a cross section of a liquid ejection unit according to the fourth embodiment. 8, the same components as those in FIG. 6 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The liquid discharge unit of the present embodiment includes a duct 33 c provided with a reflection member 34 that reflects irradiation light on the opposite surface of the UV lamp 32. By reflecting the light that has not been used for curing the UV ink mist in the duct 33c, the total amount of irradiation light in the duct 33c can be increased, and the energy applied to the ink mist can be increased. Therefore, the UV ink mist can be further cured. The surface inside the duct may be polished to form a reflective surface.

  In the present embodiment (FIG. 8), the reflection surface is provided only on the opposite surface (one surface) of the UV lamp 32 in the duct 33c. However, the present invention is not limited to this. For example, like a kaleidoscope, you may provide a reflection member (reflection surface) in all the surfaces inside a duct. The energy applied to the UV ink mist can be increased by reflecting and reusing the UV light that has not been used for curing the UV ink mist.

(Fifth embodiment)
When the ink mist can be sufficiently cured by the UV lamp 32, the cured ink mist is difficult to adhere to the amplifier substrate 20 and the like, so that a decrease in cooling efficiency can be suppressed without the filter 31. Further, by eliminating the filter 31, the cooling air amount of the fan can be fully used, so that the fan can be reduced in size and power consumption can be reduced.

  The present invention has been described in detail above using the embodiment. In these embodiments, an example of UV ink that is cured by ultraviolet rays has been described. However, the present invention is not limited to this, and a liquid using a resin material that is cured by light of various wavelengths such as visible light, infrared rays, and microwaves can be used. Curing means may be used.

  The “liquid ejection unit” is an assembly of functional parts and mechanisms integrated with a liquid ejection head, and is an assembly of parts related to liquid ejection. Here, the term “integration” includes, for example, a liquid discharge head, a functional component, and a mechanism that are fixed to each other by fastening, adhesion, engagement, and the like, and one that is held movably with respect to the other. . Further, the liquid discharge head, the functional component, and the mechanism may be configured to be detachable from each other.

  Further, the “liquid ejection device” is a device that includes a liquid ejection head or a liquid ejection unit and ejects liquid by driving the liquid ejection head. The apparatus for ejecting a liquid includes not only an apparatus capable of ejecting a liquid to a receptor to which the liquid can adhere but also an apparatus for ejecting the liquid toward the air or liquid. The “liquid ejecting apparatus” can include means related to feeding, transporting, and ejecting a liquid to which liquid can adhere, a pre-processing apparatus, a post-processing apparatus, and the like.

  For example, as a “liquid ejecting device”, an image forming device that ejects ink to form an image on a sheet, or a photo-curing resin on a stage for modeling a three-dimensional model (three-dimensional model) There is a three-dimensional modeling apparatus (three-dimensional modeling apparatus) that discharges a modeling liquid to be included.

  The “receptor” means a liquid to which liquid can adhere at least temporarily and adheres and adheres, or adheres and penetrates. Specific examples include recording media such as paper, recording paper, recording paper, film, and cloth, electronic parts such as electronic substrates and piezoelectric elements, powder layers (powder layers), organ models, and test cells. Yes, unless specifically limited, includes all those to which liquid adheres.

  The material of the “receptor” is not limited as long as liquid such as paper, thread, fiber, fabric, leather, metal, plastic, film, glass, wood, and ceramic can be attached temporarily.

  “Liquid” refers to a state having a fluidity of a viscosity of 20 mPa · s or less under the environment in which it is used. When discharging in a heated environment, the fluid may be exhibited in the heated environment, and at room temperature. It may be in a solid state that does not exhibit fluidity.

DESCRIPTION OF SYMBOLS 10 Linear actuator 15 Carriage 16 Inkjet head 17a, 17b, 32 UV lamp 18 Device base 19 Waste liquid receptacle 20 Amplifier board 21 Wiper 22 Linear stage 23 Guide rod 24 UV irradiation light 26 Cap 28 Empty discharge receptacle 30 Intake fan 31 Filter 33a, 33b 33c Duct P Recording medium

JP 2014-167949 A

Claims (10)

A liquid ejection head that ejects a liquid containing a photocurable resin that cures when irradiated with light; and
A circuit board electrically connected to the liquid ejection head;
A first light irradiation device for irradiating light to the discharged liquid;
A fan for blowing air to the circuit board;
A second light irradiation device that irradiates light upstream of the fan to the intake air flow generated by the fan;
A liquid discharge unit comprising:   The liquid ejection unit according to claim 1, wherein the circuit board is an amplifier board that amplifies a drive signal applied to the liquid ejection head.   The liquid discharge unit according to claim 1, wherein a duct is provided on an intake side of the fan to irradiate the inside of the duct with light from the second light irradiation device.   The liquid discharge unit according to claim 3, wherein the duct is formed using a material that does not transmit light of the second light irradiation device.   5. The liquid ejection unit according to claim 3, wherein at least one surface inside the duct irradiated with light of the second light irradiation device is a reflection part that reflects the irradiation light.   The liquid discharge unit according to claim 1, wherein a filter is provided on an intake side of the fan.   A liquid discharge apparatus comprising the liquid discharge unit according to claim 1. A liquid ejection head that ejects a liquid containing a photocurable resin that cures when irradiated with light; and
A circuit board electrically connected to the liquid ejection head;
A first light irradiation device for irradiating light to the discharged liquid;
A fan for blowing air to the circuit board;
A second light irradiation device for irradiating light upstream of the fan to the intake air flow generated by the fan;
A liquid ejection apparatus for ejecting the liquid by driving the liquid ejection head.   9. The apparatus according to claim 7, further comprising: a receiver on which the discharged liquid is landed, wherein the first light irradiation device performs light irradiation on the liquid landed on the receiver. Liquid ejection device.   The liquid ejecting apparatus according to claim 9, wherein the liquid is a photocurable ink containing a pigment or a dye, and the receiver is a recording medium on which an image or a character is recorded.