JP7501095B2 - Liquid ejection device - Google Patents

Description

The present invention relates to a device for discharging liquid.

In a head that ejects liquid, the liquid temperature rises and the ejection characteristics fluctuate due to the temperature rise caused by heat generated by heat-generating components such as a pressure generating means such as a piezoelectric element that ejects the liquid, a driving IC (driver IC) such as a switching circuit, and a head drive board that includes a power amplifier that is located near the head and generates a drive waveform to drive the piezoelectric element.

A known conventional system includes a container for storing a temperature-adjusted temperature-adjusting liquid (cooling liquid) and a cooling means for cooling the cooling liquid in the container, and distributes and supplies the temperature-adjusting liquid from the container to multiple heads via an outward manifold, and collects the temperature-adjusting liquid from each of the multiple heads in a return manifold and returns it to the container (Patent Document 1).

Japanese Patent Application Laid-Open No. 10-86411

However, even with the configuration disclosed in Patent Document 1, there is an issue that multiple heat generating parts cannot be cooled efficiently.

The present invention was made in consideration of the above problems, and aims to efficiently cool multiple heat generating parts.

In order to solve the above problems, a liquid ejection device according to a first aspect of the present invention comprises:
A plurality of heads for ejecting liquid;
a circulation path through which a temperature-adjusted liquid circulates;
A cooling means for cooling the temperature control liquid,
The circulation path is thermally coupled to at least two heat generating parts having different heat values,
The two heat generating parts are thermally coupled to the circulation path in ascending order of heat generation amount when the cooling means is used as a starting point ,
a liquid supply manifold that distributes and supplies the liquid to the plurality of heads;
a temperature regulating liquid supply manifold that distributes and supplies the temperature regulating liquid to the plurality of heads,
The liquid supply manifold and the temperature control liquid supply manifold are thermally coupled to each other.
The composition was as follows.

According to the present invention, multiple heat generating parts can be cooled efficiently.

1 is a schematic explanatory diagram of a printing apparatus as a liquid ejecting apparatus according to a first embodiment of the present invention. FIG. 2 is a plan view illustrating a head unit constituting a discharge unit of the device, as viewed from the nozzle surface side. FIG. 2 is an explanatory cross-sectional view of an example of a head in a short side direction (a direction perpendicular to the nozzle arrangement direction). 4 is a plan view illustrating the temperature regulating liquid flow path taken along line AA in FIG. 3. FIG. 2 is a perspective view illustrating ports for ink and temperature adjusting liquid of the head. 2 is a block diagram illustrating a liquid (ink) supply system and a temperature regulating liquid circulation path system in the first embodiment of the present invention. FIG. FIG. 4 is a perspective view illustrating an assembled state of an ink supply manifold and a temperature regulating liquid supply manifold. FIG. 4 is a cross-sectional view illustrating a temperature regulating liquid supply manifold. 4 is a front cross-sectional view for explaining in detail a temperature control liquid flow path of the temperature control liquid recovery manifold of FIG. 13 is a perspective view of a connecting portion between the temperature adjusting liquid recovery manifold and the head driving substrate. FIG. FIG. FIG. 5 is an explanatory diagram illustrating the positional relationship between a head, a temperature regulating liquid supply manifold, and a temperature regulating liquid recovery manifold; FIG. FIG. 2 is a block diagram illustrating a portion related to temperature control of a temperature control liquid; FIG. 4 is an explanatory diagram of an example of a driving waveform for increasing the temperature of a temperature control liquid. 11 is an explanatory diagram of an example of the relationship between the duty (drive frequency) of the drive waveform for increasing the temperature control liquid, and the environmental temperature and the temperature of the temperature control liquid. FIG. FIG. 11 is a block diagram illustrating a liquid (ink) supply system and a temperature regulating liquid circulation path system according to a second embodiment of the present invention. FIG. 13 is an exploded perspective view illustrating an example of a cooling member for a head having a head driving IC including a waveform generating unit and a power amplifier unit for a nozzle driving element within the head, in which the head and the cooling member are separated. 13 is a partial cross-sectional view illustrating a temperature control liquid flow path of the cooling member in a direction perpendicular to the nozzle arrangement direction. FIG. 13 is a partial cross-sectional view illustrating a direction perpendicular to the nozzle arrangement direction for explaining thermal coupling between the cooling member and a head driving IC. FIG. 13 is an explanatory diagram illustrating the configuration of a head unit and a circulation path of a temperature regulating liquid according to a third embodiment of the present invention. FIG. FIG. 13 is a perspective view illustrating a temperature control liquid circulation path of the dual head. FIG. 13 is a block diagram illustrating a liquid (ink) supply system and a temperature regulating liquid circulation path system in a fourth embodiment of the present invention. FIG. 13 is an explanatory diagram illustrating a temperature regulating fluid circulation system in a fifth embodiment of the present invention.

Embodiments of the present invention will be described below with reference to the accompanying drawings. A printing device as a device for ejecting liquid according to a first embodiment of the present invention will be described with reference to FIG. 1. FIG. 1 is a schematic diagram of the printing device.

The printing device 1 includes an input section 10 for inputting sheet material P, a pre-processing section 20, a printing section 30, a drying section 40, an unloading section 50, and an inversion mechanism section 60. In the printing device 1, the pre-processing section 20, which is a pre-processing means, applies (coats) a pre-processing liquid to the sheet material P input (supplied) from the input section 10 as necessary, the printing section 30 applies liquid to perform the required printing, the drying section 40 dries the liquid adhering to the sheet material P, and then the sheet material P is discharged to the unloading section 50.

The loading section 10 includes an input tray 11 (lower input tray 11A, upper input tray 11B) that stores multiple sheet materials P, and a feeding device 12 (12A, 12B) that separates and sends out the sheet materials P one by one from the input tray 11, and supplies the sheet materials P to the pre-processing section 20.

The pre-treatment unit 20 includes an application unit 21, which is a treatment liquid application means that applies a treatment liquid to the printing surface of the sheet material P, for example, to aggregate the ink coloring material and prevent show-through.

The printing unit 30 includes a drum 31, which is a support member (rotating body) that supports the sheet material P on its circumferential surface and rotates, and a liquid ejection unit 32 that ejects liquid toward the sheet material P supported by the drum 31.

The printing section 30 also includes a transfer cylinder 34 that receives the sheet material P sent from the pre-processing section 20 and transfers the sheet material P between the drum 31, and a transfer cylinder 35 that receives the sheet material P transported by the drum 31 and transfers it to the drying section 40.

The sheet material P transported from the pre-processing section 20 to the printing section 30 has its leading edge gripped by a gripping means (sheet gripper) provided on the transfer cylinder 34, and is transported as the transfer cylinder 34 rotates. The sheet material P transported by the transfer cylinder 34 is transferred to the drum 31 at a position opposite the drum 31.

A gripping means (sheet gripper) is also provided on the surface of the drum 31, and the leading edge of the sheet material P is gripped by the gripping means (sheet gripper). A number of suction holes are formed in a distributed manner on the surface of the drum 31, and the suction means generates a suction airflow that flows inward from the required suction holes of the drum 31.

Then, the sheet material P transferred from the transfer cylinder 34 to the drum 31 has its leading edge gripped by the sheet gripper, is adsorbed and supported on the drum 31 by the suction airflow from the suction means, and is transported as the drum 31 rotates.

The liquid ejection section 32 is equipped with ejection units 33 (33A to 33D) which are liquid ejection means. For example, ejection unit 33A ejects cyan (C) liquid, ejection unit 33B ejects magenta (M) liquid, ejection unit 33C ejects yellow (Y) liquid, and ejection unit 33D ejects black (K) liquid. In addition, ejection units that eject special liquids such as white and gold (silver) can also be used.

The ejection operation of each ejection unit 33 of the liquid ejection section 32 is controlled by a drive signal corresponding to the printing information. When the sheet material P supported on the drum 31 passes through the area facing the liquid ejection section 32, liquid of each color is ejected from the ejection unit 33, and an image corresponding to the printing information is printed.

The drying section 40 dries the liquid that has been applied to the sheet material P by the printing section 30. This causes the water content in the liquid and other liquid components to evaporate, the colorant contained in the liquid to be fixed on the sheet material P, and curling of the sheet material P is suppressed.

The reversing mechanism 60 is a mechanism that reverses the sheet material P using a switchback method when performing double-sided printing on the sheet material P that has passed through the drying section 40, and the reversed sheet material P is sent back upstream of the transfer cylinder 34 through the conveying path 61 of the printing section 30.

The discharge section 50 is equipped with a discharge tray 51 on which multiple sheet materials P are stacked. The sheet materials P transported through the reversing mechanism section 60 are stacked and held on the discharge tray 51 in sequence.

Next, an example of a head unit constituting a discharge unit will be described with reference to FIG. 2. FIG. 2 is a plan view of the head unit as viewed from the nozzle surface side.

The head unit 300 has multiple heads 100 that eject liquid arranged in a staggered pattern on a head mounting member 302.

Each head 100 has multiple nozzle rows (four rows are shown here as an example, but this is not limited to this) in which multiple nozzles 104 that eject liquid are arranged.

Next, an example of the head 100 will be described with reference to Figures 3 to 5. Figure 3 is a cross-sectional view of the head in the short direction (the direction perpendicular to the nozzle arrangement direction), Figure 4 is a plan view of the temperature control liquid flow path along line A-A in Figure 3, and Figure 5 is a perspective view explaining the ink and temperature control liquid ports of the head.

The head 100 is formed by sequentially laminating a nozzle plate 101 in which nozzles 104 are formed, a flow path plate 102 which forms flow paths such as pressure chambers 106 which communicate with the nozzles 104, and a vibration plate 103 which forms the wall surface of the pressure chambers 106. The head 100 also has a piezoelectric actuator 111 as a pressure generating means, and a frame member 120 which is a housing part which also serves as a common flow path member.

The piezoelectric actuator 111 has a plurality of columnar piezoelectric elements 112 fixed on a base member 113, and the piezoelectric elements 112 are joined to the vibration plate 103. In addition, a wiring member 115 such as a flexible wiring board is connected to the piezoelectric elements 112.

The frame member 120, which also serves as a common flow path member, forms a common supply flow path 110 that supplies the liquid (ink) to be ejected to the pressure chamber 106.

A temperature control liquid flow path member 131 is joined to this frame member 120 to form a temperature control liquid flow path 130 in the head 100 through which a temperature control liquid (liquid whose temperature is adjusted) flows. The temperature control liquid flow path member 131 has a temperature control liquid supply port 132a that supplies temperature control liquid to the temperature control liquid flow path 130, and a temperature control liquid recovery port 133a that recovers the temperature control liquid to the outside.

As a result, the common supply flow path 110, which is the ink flow path, and the temperature adjustment liquid flow path 130 are thermally coupled within the head 100. In addition, the frame member 120, which also serves as the housing part of the head 100, forms the wall surface of the adjustment liquid flow path 130, and is naturally thermally coupled to the temperature adjustment liquid flow path 130.

A case member 150 and a cover member 151 are layered in sequence on the temperature adjustment liquid flow path member 131.

As shown in FIG. 5, the case member 150 has ink supply ports 122, 122 that supply ink to the common supply flow path 110, a temperature adjustment liquid supply port 132 connected to the temperature adjustment liquid supply port 132a of the temperature adjustment liquid flow path 130, and a temperature adjustment liquid recovery port 133 connected to the temperature adjustment liquid recovery port 133a.

Next, the liquid (ink) supply system and temperature control liquid circulation path system in the first embodiment of the present invention will be described with reference to Figures 6 to 8. Figure 6 is a block diagram of the liquid (ink) supply system and temperature control liquid circulation path system, Figure 7 is a perspective view of the assembled state of the ink supply manifold and temperature control liquid supply manifold, and Figure 8 is a cross-sectional view of the temperature control liquid manifold.

The ink supply system includes a liquid tank (ink tank) 401 that stores liquid (ink) to be supplied to the head 100, and an ink supply manifold 402, which is a liquid supply manifold that distributes and supplies the ink supplied from the liquid tank 401 to the multiple heads 100. The ink supply manifold 402 and each head 100 are connected by a supply path 403 such as a supply tube.

As shown in FIG. 7, the ink supply manifold 402 is a cylindrical member with an ink flow path 420 (see FIG. 13 described below) formed therein, and has an inlet port 421 through which ink is supplied from the ink tank 401, and an outlet port 422 through which ink is supplied to each head 100.

The temperature control liquid circulation system includes a temperature control liquid tank 501 that stores the temperature control liquid 510, a liquid delivery pump 502 that delivers the temperature control liquid 510, a cooler 511 that is a cooling means for cooling the temperature control liquid 510, a temperature control liquid supply manifold 505 that distributes and supplies the temperature control liquid 510 to each head 100, and a temperature control liquid recovery manifold 506 that recovers the temperature control liquid 510 from each head 100.

As shown in FIG. 8, the temperature control liquid supply manifold 505 is a plate-shaped member having a flow path for the temperature control liquid 510 formed therein, and has an inlet port 555 through which the temperature control liquid is supplied from the heat exchanger 503, and an outlet port 556 through which the temperature control liquid is supplied to each head 100.

The temperature-adjusting liquid supply manifold 505 includes a manifold body 552 having multiple liquid flow paths 551a-551d formed therein along the longitudinal direction, and folded-back caps 553 attached to both ends of the manifold body 552.

The liquid flow path 551d is provided with an outlet port 556 that supplies the temperature adjustment liquid 510 to each head 100. The temperature adjustment liquid 510 is supplied from the outlet port 556 to the temperature adjustment liquid supply port 132 via the supply path 513.

As shown in FIG. 7, the temperature adjustment liquid supply manifold 505 is fitted with the ink supply manifold 402, and the temperature adjustment liquid supply manifold 505 and the ink supply manifold 402 are thermally coupled.

The cooler 511 is, for example, a radiator.

The temperature control liquid supply manifold 505 and the temperature control liquid supply port 132 of each head 100 are connected by a supply path 513 such as a supply tube, and the temperature control liquid recovery port 133 of each head 100 and the temperature control liquid recovery manifold 506 are connected by a recovery path 514 such as a recovery tube.

By driving the liquid delivery pump 502, the temperature control liquid 510 stored in the temperature control liquid tank 501 circulates through the circulation path 500, passing through the liquid delivery pump 502, the cooler 511, the temperature control liquid supply manifold 505, each head 100, the temperature control liquid recovery manifold 506, and back to the temperature control liquid tank 501.

The heat generating portion of the head drive board 160, which includes a drive waveform generating section that applies the drive waveform to the piezoelectric actuators 111 of the multiple heads 100 and a power amplifier that amplifies the waveform, is thermally coupled to the temperature adjustment liquid recovery manifold 506.

In a system configured in this manner, the temperature control liquid 510 is pumped up from the temperature control liquid tank 501 by the liquid supply pump 502, passes through a cooler 511 that cools the temperature control liquid 510, and is distributed to each head 100 from the temperature control liquid supply manifold 505.

The temperature control liquid 510 passes through the temperature control liquid flow path 130 of each head 100, thereby cooling the frame member 120 (housing portion) of each head 100, and after passing through each head 100, is collected in the temperature control liquid collection manifold 506, after which it cools the head drive board 160 (drive circuit portion), thereby cooling the power amplifier portion, etc., and returns to the temperature control liquid tank 501.

Meanwhile, ink is supplied from the ink tank 401 to the ink supply manifold 402 and distributed to each head 100.

Because the temperature adjustment liquid supply manifold 505 and the ink supply manifold 402 are thermally coupled, the ink temperature in the ink supply manifold 402 is adjusted to a temperature equivalent to that of the temperature adjustment liquid 510 before the ink flows into each head 100. This makes the temperature of the ink supplied from the ink supply manifold 402 uniform, and suppresses the temperature gradient between the heads 100 and on the nozzle rows 103 and 104 (suppression of the temperature gradient in the nozzle row direction).

Here, the circulation path 500 of the temperature control liquid 510 is thermally coupled to the frame member 120, which serves as the housing of the head 100, which is the heat generating part, and to the head drive board 160, which is equipped with a drive waveform generating part and a power amplifier that amplifies the waveform.

In this case, the amount of heat generated by the frame member 120 is smaller than the amount of heat generated by the head drive board 160. Therefore, the frame member 120 and the head drive board 160, which are the two heat generating parts thermally coupled to the circulation path 500, are thermally coupled to the circulation path 500 in the order of the relatively smallest amount of heat generated, that is, in this embodiment, the frame member 120 of the head 100 is thermally coupled to the circulation path 500 in the order of the head drive board 160.

This allows the temperature control liquid to cool the parts in order of decreasing heat generation, resulting in efficient cooling.

In other words, if a heat generating part with a small heat generation output is placed downstream of a heat generating part with a large heat generation output, the cooled temperature control liquid will be warmed by the heat generating part with a large heat generation output, causing the temperature to rise, and there is a risk that even the heat generated by the heat generating part with a small heat generation output will not be able to be cooled.

In contrast, by cooling the heat generating parts in sequence starting with the parts that generate the least amount of heat, as in the present embodiment, it is possible to reliably cool the heat generating parts without causing a sudden increase in the temperature of the temperature control liquid.

Next, the temperature adjustment liquid collection manifold and the thermal coupling between the temperature adjustment liquid collection manifold and the head drive board 160 will be described with reference to Figures 9 to 12. Figure 9 is a front cross-sectional view for explaining in detail the temperature adjustment liquid flow path of the temperature adjustment liquid collection manifold. Figure 10 is a perspective view of the coupling portion between the temperature adjustment liquid collection manifold and the head drive board 160, Figure 11 is an exploded perspective view of the same, and Figure 12 is a side view of the same coupling portion.

The temperature control liquid recovery manifold 506 has a temperature control liquid flow path 561 formed therein through which the temperature control liquid 510 supplied from the head 100 through the recovery path 514 flows in the direction of arrow A. The temperature control liquid recovery manifold 506 also has an inlet port 565 that connects to the multiple recovery paths 514, and an outlet port 566 that discharges the temperature control liquid into the temperature control liquid tank 501.

The temperature adjustment liquid flow path 561 has multiple liquid flow paths along the longitudinal direction and has return flow paths at both ends.

A power amplifier 161 consisting of a MOS-FET or the like that amplifies the drive waveform is mounted on the head drive board 160, and a heat sink 162 is provided in contact with the power amplifier 161.

The heat sink 162 of the head drive board 160 and the temperature adjustment liquid recovery manifold 506 are fixed via a thermally conductive sheet 163, thereby thermally coupling the temperature adjustment liquid recovery manifold 506 and the power amplifier section 161 of the head drive board 160.

Next, the positional relationship between the head 100, the temperature control liquid supply manifold 505, and the temperature control liquid recovery manifold 506 will be described with reference to FIG. 13. FIG. 13 is an explanatory diagram for the same description.

The temperature adjustment liquid collection manifold 506 and the temperature adjustment liquid supply manifold 505 are disposed above the head 100. Therefore, in this embodiment, the ink supply manifold 402, which is thermally coupled to the temperature adjustment liquid supply manifold 505, is also disposed above the head 100.

The ink supply manifold 402 is connected to the ink supply port 122 of the head 100 via an ink supply path 403. The temperature adjustment liquid supply manifold 505 is connected to the temperature adjustment liquid supply port 132 of the head 100 via a supply path 513. The temperature adjustment liquid recovery manifold 506 is connected to the temperature adjustment liquid recovery port 133 of the head 100 via a recovery path 514.

By arranging the temperature adjustment liquid collection manifold 506 and the temperature adjustment liquid supply manifold 505 above the head 100, high image quality can be obtained without reducing the nozzle density (head arrangement density) of the head 100. In addition, the distance between the ink supply path 403 and the temperature adjustment liquid supply path 513 can be shortened, and temperature changes within each supply path can be kept small.

The frame member 120 of the head 100, which generates less heat than the head drive board 160, is positioned below the head drive board 160, and is thermally coupled to the circulation path 500 in the order of the frame member 120 of the head 100 and the head drive board 160. The head drive board 160, which is thermally coupled to the temperature adjustment liquid recovery manifold 506, is positioned above the head 100. This allows for efficient cooling and suppresses temperature rise in the head 100.

The head unit 300, the temperature adjustment liquid collection manifold 506, and the temperature adjustment liquid supply manifold 505 are integrated by the cover 1000. This improves maintainability.

Next, the parts related to the temperature control of the temperature control liquid will be explained with reference to the block diagram in Figure 14.

The temperature control liquid temperature control means 801 inputs the detection results of an environmental temperature sensor 811 that detects the environmental temperature TH5, and a temperature control liquid sensor 812 that detects the temperature TH1 of the temperature control liquid at the inlet of the cooler 511.

The temperature adjustment liquid temperature control means 801 also inputs the detection results of the rotation speed sensor 814, which detects the rotation speed of the radiator fan that constitutes the cooler 511.

Then, the temperature adjustment liquid temperature control means 801 controls the operation of the fan that constitutes the cooler 511 based on these input detection results.

Next, we will provide an overview of temperature control operation when the ambient temperature is below 25°C.

The temperature control liquid is controlled to a specified temperature range (25°C to 36.5°C). When starting up the device in a low-temperature environment, it is necessary to raise the ink temperature to a specified temperature. Therefore, a temperature-raising drive waveform that is off the resonance point at which ink is not ejected is applied to the piezoelectric actuator 111 of the head 100, and the temperature control liquid 510 is heated by the heat generated by the MOS-FET of the head drive board 160 and the heat generated by the piezoelectric actuator 111. By circulating the temperature control liquid 510, the circulation path 500 and the ink supply path inside and in front of the head 100 are heated to a certain temperature.

When performing heating control of the temperature-adjusted liquid 510, if the temperature of the temperature-adjusted liquid associated with the ambient temperature is below a predetermined temperature (threshold temperature) of 25°C, the cooler 511 is turned off, the temperature TH1 of the temperature-adjusted liquid 510 at the inlet of the cooler 511 in the circulation path 500 is detected, and the heat generation duty of the piezoelectric actuator 111 is controlled to perform heating control so that the temperature-adjusted liquid 510 becomes 25°C.

In addition, when the temperature of the temperature adjustment liquid 510 reaches or exceeds the threshold temperature of 25°C, the heat generation of the MOS-FET of the head drive board 160 and the heating control by the piezoelectric actuator 111 are stopped, and the printer transitions to a print standby state.

Furthermore, when continuous printing is started and the temperature of the circulating temperature control liquid 510 reaches or exceeds the threshold temperature of 25°C, the cooler 511 is driven to cool the temperature control liquid 510 to within the ambient temperature + 3°C.

Here, the cooling capacity of the cooler 511 is set to be capable of cooling the amount of heat generated corresponding to the maximum amount of ink in the head unit 300. The cooling capacity is set according to the amount of heat generated by the head drive board 160, which includes a power amplifier that amplifies the drive waveform applied to the piezoelectric actuator 111 of the head 100, the amount of heat generated by the piezoelectric actuator 111 in the head 100, and the amount of heat generated by the head drive IC that selects the piezoelectric element 112 that provides the drive waveform for the piezoelectric actuator 111 of the head 100.

Next, the operation control during start-up in a low-temperature environment will be described with reference to Figs. 15 and 16. Fig. 15 is an explanatory diagram of an example of a drive waveform for increasing the temperature control liquid temperature, and Fig. 16 is an explanatory diagram of an example of the relationship between the duty (drive frequency) of the drive waveform for increasing the temperature control liquid temperature and the environmental temperature and temperature control liquid temperature.

When starting up in a low-temperature environment, the head temperature, ink temperature, and temperature control liquid temperature are the same as in a low-temperature environment, so the ink viscosity increases significantly compared to the viscosity at room temperature, and the target ejection characteristics cannot be obtained.

Therefore, when starting up the device in a low-temperature environment, a heating drive waveform, as shown in FIG. 15, which is off-resonance, is applied to the head drive board 160 and the piezoelectric element 112 of the head 100.

At the same time, the liquid supply pump 502 is driven to circulate the temperature control liquid, and the temperature of the temperature control liquid, the circulation path 500, the head 100 is raised, and the temperature is increased to near the room temperature environment temperature through the thermal coupling between the ink supply manifold 402 and the temperature control liquid supply manifold 505.

At this time, the amount of heat generated can be controlled by controlling the drive frequency of the heating drive waveform applied to the head drive board 160 and the piezoelectric element 112. For example, when the ambient temperature is 10°C, the head drive board 160 is heated with a heat generation amount of 8 kW (40 KHz), and the temperature in the circulation path 500 is rapidly raised. As the room temperature of the ink temperature control target is reached, the drive frequency is reduced to reduce the amount of heat generated in order to avoid overshooting.

For example, as shown in FIG. 16, the drive frequency (duty) of the temperature-raising drive waveform applied to the head drive circuit board is changed according to the temperature TH1 of the temperature-control liquid flowing into the radiator that constitutes the cooler 511. As described above, the temperature TH1 is detected by the temperature-control liquid sensor 812 at the inlet of the cooler, which is the temperature that controls the cooler.

Each head drive board 160 is equipped with eight drive wave generating circuits and a drive waveform amplifier, and the maximum heat generation of the head drive board is 290 W per board. In addition, eleven head drive boards 160 are installed corresponding to the eleven heads that make up one color nozzle array, so the maximum heat generation of the four colors is 12 kW, and low-temperature warm-up time is short.

The waveform of the driving waveform for heating shown in Figure 15 is a waveform that is off the resonance point of the pressure chamber 106, and the waveform length is set to 14 μm, so that the driving frequency is variable to control the amount of heat generated. For example, since the period of 60 KHz is 16.7 μs, if a waveform is created with a period of 14 μs, it is possible to apply up to 60 KHz. In this embodiment, a table is created that controls the amount of heat generated by setting the amount of heat generated when 40 KHz is applied to 100% (see Figure 16 above).

Next, a second embodiment of the present invention will be described with reference to FIG. 17. FIG. 17 is a block diagram of a liquid (ink) supply system and a temperature control liquid circulation path system in this embodiment.

In this embodiment, the head 100 is provided with a cooling member 570 that cools the head driving IC 116 that drives the head actuator, including the waveform generating section and power amplifier section of the nozzle driving element mounted on the wiring member 115 of the head 100.

The head drive IC 116 in this embodiment is composed of an integrated circuit in which the waveform generation section and power amplifier section mounted on the head drive board 160 in the first embodiment are densely integrated for each nozzle row, and includes a waveform generation section and an actuator that apply the waveform to the piezoelectric actuator 111 of the head 100, a power amplifier section that amplifies the waveform, and circuits for controlling each nozzle.

Then, the temperature control liquid is supplied from the temperature control liquid supply manifold 505 to the frame member 120 of the head 100, the temperature control liquid that has passed through the frame member 120 is supplied to the cooling member 570, and the temperature control liquid that has passed through the cooling member 570 is collected in the temperature control liquid collection manifold 506.

Here too, the frame member 120, which is the housing part of the head 100, and the head driving IC 116 are arranged in the circulation path 500 as two heat generating parts with different heat generation amounts. In this embodiment, the circulation path 500 starts from the cooler 511, and is arranged downstream of the cooler 511 in order of decreasing heat generation, in this case the frame member 120, which is the housing part, and the head driving IC 116.

This allows the temperature control liquid to cool in order of decreasing heat generation, resulting in efficient cooling.

Next, an example of the cooling member 570 will be described with reference to Figures 18 to 20. Figure 18 is an exploded perspective view of the head and cooling member separated. Figure 19 is a partial cross-sectional view in a direction perpendicular to the nozzle arrangement direction to explain the temperature control liquid flow path of the cooling member, and Figure 20 is a partial cross-sectional view in a direction perpendicular to the nozzle arrangement direction to explain the thermal coupling between the cooling member and the head driving IC 116.

The cooling member 570 has a temperature control liquid flow path 572 formed in the heat receiving portion 571 through which the temperature control liquid flows. The temperature control liquid flow path 572 has a supply port 573 and a recovery port 574.

The heat receiving portion 571 of this cooling member 570 is thermally coupled to the surface of the head driving IC 116 mounted on the wiring member 115 via a heat transfer sheet 575, and a temperature control liquid flow path 572 through which the temperature control liquid 510 flows is disposed adjacent to the head driving IC 116.

As a result, as shown by arrow A in Figures 18 and 19, the temperature adjustment liquid 510 flows through the temperature adjustment liquid flow path 572 of the cooling member 570, cooling the driver IC 116 and suppressing heat generation, and suppressing an increase in ink temperature due to heat dissipation from the head driving IC 116.

Next, a third embodiment of the present invention will be described with reference to Figs. 21 and 22. Fig. 21 is an explanatory diagram for explaining the configuration of the head unit and the circulation path of the temperature control liquid according to the third embodiment, and Fig. 22 is a perspective explanatory diagram for explaining the temperature control liquid circulation path of the dual head.

The head unit 300 is made up of two sets of heads (dual heads) 100, 100 that eject liquid, arranged in a staggered pattern.

22, the temperature control liquid 510 is supplied from the temperature control liquid supply manifold to the temperature control liquid supply port 132 of one of the two heads 100, 100, and the temperature control liquid that has passed through the frame member 120 of one of the heads 100 is collected from the temperature control liquid recovery port 133. The temperature control liquid 510 collected from one of the heads 100 is supplied to the temperature control liquid supply port 132 of the other head 100, and the temperature control liquid 510 that has passed through the frame member 120 of the other head 100 is collected from the temperature control liquid recovery port 133.

The temperature control liquid 510 collected from the temperature control liquid collection port 133 of the other head 100 is collected in the temperature control liquid collection manifold 506 through the cooling member 570.

For each head 100, ink is supplied to the ink supply port 122 as shown by the dashed arrow B in Figure 22.

Next, a fourth embodiment of the present invention will be described with reference to FIG. 23. FIG. 23 is a block diagram of a liquid (ink) supply system and a temperature control liquid circulation path system in this embodiment.

The circulation path 500 is thermally coupled to three heat generating parts with different heat values: the frame member 120 that constitutes the housing part of the head 100, the base member 113 that constitutes the piezoelectric actuator 11, and the head driving IC 116.

At this time, the frame member 120, the piezoelectric actuator 11, and the head driving IC 116, which have different amounts of heat generation, are thermally coupled to the circulation path 500 in the order of the relatively smallest amount of heat generation, that is, the frame member 120, the base member 113, and the head driving IC 116, when the cooler 511 is used as the starting point.

This allows for efficient cooling.

Next, a fifth embodiment of the present invention will be described with reference to FIG. 24. FIG. 24 is an explanatory diagram for explaining the temperature control liquid circulation system in this embodiment.

In this embodiment, a temperature control liquid supply manifold 505 (505A to 505D) and a temperature control liquid recovery manifold 506 (506A to 506D) are provided to correspond to the multiple head units 300 (33A to 33D) including the multiple heads 100 of the first embodiment.

The system is equipped with a common temperature-adjusting liquid tank 501. Temperature-adjusting liquid 510 is branched and supplied from the common temperature-adjusting liquid tank 501 to temperature-adjusting liquid supply manifolds 505A and 505B via a liquid supply pump 502A and a radiator 511A (direct connection between 511A1 and 511A2).

The temperature control liquid 510 is also branched and supplied from the common temperature control liquid tank 501 to the temperature control liquid supply manifolds 505C and 505D via the liquid supply pump 502B and the radiator 511B (direct connection between 511B1 and 511B2).

Meanwhile, the temperature adjustment liquid 510 that has passed through the head unit 300 is collected by the temperature adjustment liquid collection manifolds 506 (506A to 506D) and then collected together and returned to the temperature adjustment liquid tank 501.

Therefore, the circulation path 500A runs from the temperature adjustment liquid tank 501 through the liquid supply pump 502A, the radiators 511A1 and 511A2, the temperature adjustment liquid supply manifolds 505A and 505B, the head units 300A and 33B, the temperature adjustment liquid recovery manifolds 506A and 506B, and back to the temperature adjustment liquid tank 501.

Similarly, the circulation path 500B runs from the temperature adjustment liquid tank 501 through the liquid supply pump 502B, the radiators 511B1 and 511B2, the temperature adjustment liquid supply manifolds 505C and 505D, the head units 300C and 33D, the temperature adjustment liquid recovery manifolds 506C and 506D, and back to the temperature adjustment liquid tank 501.

In addition, each temperature-adjusting liquid recovery manifold 506 is thermally coupled to the head drive board 160 to cool the power amplifier that amplifies the drive waveform of the MOS-FET or the like mounted on the head drive board 160.

Also, in this embodiment, as in FIG. 13, the frame member 120 of the head 100, which has a smaller amount of heat generation than the head drive board 160, is placed below the head drive board 160, and the frame member 120 of the head 100 and the head drive board 160 are thermally coupled to the circulation path 500 in that order. The head drive board 160, which is thermally coupled to the temperature adjustment liquid recovery manifold 506, is placed above the head 100. This allows for efficient cooling and suppresses temperature rise in the head 100.

In this embodiment, four radiators 511 are used as the cooling means, and a mixed connection is configured in which two radiators are connected in series and then connected in parallel, but it is also possible to configure four radiators 511 in parallel as in the second embodiment. Furthermore, it is also possible to arrange a cooling means in which multiple radiators are connected in series, in parallel, or in a mixture of series and parallel connections.

In the present application, the liquid to be ejected may have a viscosity and surface tension that allows it to be ejected from the head, and is not particularly limited, but it is preferable that the viscosity is 30 mPa·s or less at room temperature and pressure, or by heating or cooling. More specifically, the liquid may be a solution, suspension, emulsion, etc. that contains a solvent such as water or an organic solvent, a colorant such as a dye or pigment, a functionalizing material such as a polymerizable compound, a resin, or a surfactant, a biocompatible material such as DNA, amino acids, proteins, or calcium, an edible material such as a natural dye, etc., and these can be used for applications such as inkjet ink, surface treatment liquid, a liquid for forming a component of an electronic element or a light-emitting element, an electronic circuit resist pattern, a material liquid for three-dimensional modeling, etc.

"Head" includes devices that use piezoelectric actuators (laminated piezoelectric elements and thin-film piezoelectric elements), thermal actuators that use electrothermal conversion elements such as heating resistors, and electrostatic actuators consisting of a vibration plate and opposing electrodes as energy sources for ejecting liquid.

In addition, "devices that eject liquid" include not only devices that can eject liquid onto objects to which the liquid can adhere, but also devices that eject liquid into air or liquid.

This "liquid ejecting device" can also include means for feeding, transporting, and discharging items onto which liquid can be attached, as well as pre-processing devices and post-processing devices.

For example, examples of "devices that eject liquid" include image forming devices that eject ink to form an image on paper, and three-dimensional modeling devices that eject modeling liquid onto a powder layer formed by layering powder to form a three-dimensional object.

In addition, a "liquid ejecting device" is not limited to devices that use ejected liquid to visualize meaningful images such as letters and figures. For example, it also includes devices that form patterns that have no meaning in themselves, and devices that create three-dimensional images.

The above phrase "something to which liquid can adhere" refers to something to which liquid can adhere at least temporarily, and to which the liquid adheres and sticks, or adheres and penetrates. Specific examples include media such as paper, recording paper, film, and cloth, electronic circuit boards, electronic components such as piezoelectric elements, powder layers, organ models, and testing cells, and unless otherwise specified, includes all things to which liquid can adhere.

The above-mentioned "materials to which liquid can adhere" include paper, thread, fiber, cloth, leather, metal, plastic, glass, wood, ceramics, and other materials to which liquid can adhere even temporarily.

In addition, the "liquid ejection device" may be a device in which a liquid ejection head and an object to which liquid can be attached move relatively, but is not limited to this. Specific examples include a serial type device in which the liquid ejection head moves, and a line type device in which the liquid ejection head does not move.

Other examples of "liquid ejecting devices" include treatment liquid application devices that eject treatment liquid onto paper to apply the treatment liquid to the surface of the paper for purposes such as modifying the surface of the paper, and spray granulation devices that spray a composition liquid in which raw materials are dispersed through a nozzle to granulate the raw material into fine particles.

In this application, the terms image formation, recording, printing, copying, printing, modeling, etc. are all synonymous.

REFERENCE SIGNS LIST 1 Printing device 10 Carry-in section 20 Pre-processing section 30 Printing section 31 Drum 40 Drying section 50 Carry-out section 60 Reversing mechanism section 33 Discharge unit 100 Liquid discharge head (head)
116 Head driving IC
160 Head drive substrate 402 Ink supply manifold (liquid supply manifold)
505 Temperature-adjusting liquid supply manifold 506 Temperature-adjusting liquid recovery manifold 511 Cooler (cooling means)
570 Cooling member

Claims (9)

A plurality of heads for ejecting liquid;
a circulation path through which a temperature-adjusted liquid circulates;
A cooling means for cooling the temperature control liquid,
The circulation path is thermally coupled to at least two heat generating parts having different heat values,
The two heat generating parts are thermally coupled to the circulation path in ascending order of heat generation amount when the cooling means is used as a starting point,
a liquid supply manifold that distributes and supplies the liquid to the plurality of heads;
a temperature regulating liquid supply manifold that distributes and supplies the temperature regulating liquid to the plurality of heads,
2. A liquid ejection device, comprising: a liquid supply manifold and a temperature-adjusting liquid supply manifold, the liquid supply manifold and the temperature-adjusting liquid supply manifold being thermally coupled to each other. the heat generating section includes a housing section of the head, a pressure generating means, and a drive circuit section;
2. The liquid ejecting device according to claim 1, wherein the heat generation amount is, in order from the smallest to the smallest, the housing, the pressure generating means and the drive circuit. 3. The liquid ejection device according to claim 1, further comprising a temperature control liquid recovery manifold that recovers the temperature control liquid from the plurality of heads. 4. The liquid ejection device according to claim 3, wherein the temperature-adjusting liquid recovery manifold and a drive circuit section of the head are thermally coupled. the drive circuit unit includes a power amplifier unit that amplifies a drive waveform to be applied to the head,
5. The liquid ejection device according to claim 4, wherein a heat sink thermally coupled to the power amplifier section is thermally coupled to the temperature-adjusting liquid recovery manifold. When the environmental temperature is less than a threshold value, the cooling means is turned off;
The liquid ejecting device according to claim 4 or 5, further comprising a control means for applying a waveform to the head that does not eject the liquid, thereby driving the drive circuit unit to generate heat and heat the temperature-adjusting liquid to the threshold value. 7. The liquid ejecting device according to claim 1, wherein the liquid flow path and the temperature regulating liquid flow path are thermally coupled within the head. 2. The liquid discharge device according to claim 1, wherein, when the cooling means is taken as a starting point, the heat generating portion which generates a relatively smaller amount of heat of the two heat generating portions is disposed below the heat generating portion which generates a larger amount of heat. A plurality of heads that eject liquid of different colors;
A cooling means for cooling the temperature control liquid;
a plurality of liquid supply manifolds that distribute and supply the liquid to the plurality of heads;
a plurality of temperature regulating liquid supply manifolds that distribute and supply the temperature regulating liquid to the plurality of heads;
the liquid supply manifold and the temperature regulating liquid supply manifold are thermally coupled to each other;
The temperature regulating liquid is supplied from the cooling means to each of the plurality of temperature regulating liquid supply manifolds.

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