JP3327726B2 - Ink jet recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid ejecting apparatus,
More specifically, the present invention relates to a liquid ejecting apparatus that performs printing by discharging a recording liquid toward a recording material using thermal energy, and more particularly to a liquid ejecting apparatus that is suitable for performing continuous printing for a long time.

[0002]

2. Description of the Related Art For example, a liquid ejecting apparatus such as an ink jet recording apparatus includes a recording head (hereinafter referred to as a thermal recording head) for discharging a recording liquid based on data signals from a plurality of discharge ports using thermal energy. The recording is performed by causing the discharged droplets to land on a recording material such as paper or cloth. This type of printing apparatus is widely used in general printers and facsimile machines. Since the change affects recording quality, it is necessary to keep these temperature conditions within a desired range.

In order to control the temperature of the conventional thermal recording head, it is necessary to increase or decrease the drive time during the recording cycle, that is, the power supply time to the discharge energy generator (eg, heater).
Alternatively, a method of intermittently energizing a heating element (for example, a heater) for heating a head based on a temperature detected by a thermal recording head portion, or a thermal recording head as disclosed in JP-A-61-211045. By providing a heater for heating the head and a temperature detecting means in the unit and providing a blower in the apparatus, and controlling the driving of the heater and the blower based on a detection signal from the temperature detecting means, the thermal recording head section Methods such as maintaining the temperature in the proper droplet formation range have been used.

[0004]

When a fluid is used as a means for controlling the temperature, as in the case of the blower, the temperature of the fluid itself has a considerable influence on the temperature control ability. When the temperature of the fluid changes depending on the temperature, the temperature control ability also changes, and it is difficult to control the temperature within a stable temperature range regardless of the ambient temperature. Further, in the case of a thermal recording head having a large heat value, at a high environmental temperature, there is a possibility that the temperature of the thermal recording head unit (head unit) cannot be controlled and maintained within a predetermined temperature range by a fluid at the environmental temperature. there were.

It is an object of the present invention to provide a liquid ejecting apparatus capable of always performing stable temperature control and performing stable ejection for a thermal recording head unit having a large change in environment and a large amount of heat as described above. Aim.

[0006]

In order to achieve the above-mentioned object, the present invention provides a method for driving a heater formed on a substrate by energizing the heater.
In using the heat energy generated by dynamic
Using a print head that discharges ink
In an ink jet recording apparatus that performs recording by discharging ink, a heater that discharges ink by a print signal is driven.
To eject ink, and the print signal is turned off.
Power to the printer so that it does not eject ink.
Drive to control recording by the recording head.
Drive control means for controlling and the heater of the substrate are formed.
Fluid into the fluid passages on the opposite side of the
Cools the recording head by circulating at a constant flow rate
Cooling means, temperature control means for controlling the temperature of the fluid, and temperature detection means for detecting the temperature of the recording head
And the temperature control together with the control by the drive control means.
Using the fluid controlled to a predetermined temperature by control means
The recording head is controlled to be cooled by the cooling means.
And control means for controlling the temperature.
According to the temperature of the recording head detected by the detecting means.
Changing the control temperature of the fluid by the temperature control means.
It is characterized by doing.

[0007]

[0008]

According to the present invention, the fluid passage is controlled to a predetermined temperature.
Circulated fluid at a constant flow rate,
Change the fluid control temperature according to the printhead temperature.
With this, the temperature of the thermal recording head can be stably discharged.
The desired temperature can be maintained .

Further, the control operation can be simplified by continuously circulating the fluid through the fluid passage. Further, the flow rate and the flow rate of the fluid are appropriately set so that the fluid is continuously circulated through the fluid passage. By supplying or circulating the heat, the temperature control can be appropriately performed with good responsiveness without providing the heating means in the thermal recording head unit.

[0010]

Embodiments of the present invention will be described below in detail and specifically with reference to the drawings.

[ Basic Configuration Example 1 ] FIGS. 2 and 3 show a configuration example of a textile printing apparatus as a preferred example of a serial type ink jet recording apparatus to which the present invention is applied. Here, reference numeral 1 denotes a fabric of a recording material to be printed by the textile printing apparatus, which is held in a state wound around the unwinding roller 11, and has a predetermined shape from the unwinding roller 11 via the intermediate rollers 13 and 15. At a feeding speed of the printing means 1000 in a stretched state. 1
Reference numerals 7 and 19 designate a feed roller and an intermediate roller for guiding the fabric 1 printed by the printing means 1000 to the take-up roller 21 in the recording apparatus.

Reference numeral 100 denotes conveying means for guiding the fabric 1 to the printing position; 110 and 120, conveying rollers and a belt driving roller between which an endless conveying belt 130 is stretched; and 140, a cloth on the conveying belt 130. 1 is a platen roller for holding the roller 1 in an extended state. On the other hand, the printing means 1000 includes thermal recording head units 1100, 1100 mounted on a head carriage 1010, and the thermal recording head unit 110 during movement scanning of the head carriage 1010 in a direction perpendicular to the plane of FIG.
From 0 and 1100, a plurality of types of recording liquids for textile printing (hereinafter, simply referred to as ink) are discharged toward the fabric 1, and textile printing is performed.

1020 and 1022 are the carriage 10
Guide bar and guide rail for guiding the movement of 10,
1030 is a drive motor for driving the carriage 1010,
Reference numeral 1032 denotes a timing belt which is connected to the carriage 1010 and is driven at a predetermined timing according to printing by the drive motor 1030. Reference numeral 1040 denotes a support frame for holding the printing means 1000, which further deviates from the printing position on the fabric 1. As shown in FIG. 3, a recovery mechanism 1200 for performing a recovery operation by suctioning ink from an ink discharge port (not shown) of the thermal recording head units 1100 and 1100 and a waste ink tank 1210 for receiving discharged ink are provided below. Have been. 101
Reference numeral 2 denotes a bearing member such as a ball bearing fixed to the head carriage 1010 side.
The carriage 1010 moves along the guide rail 1020 via the.

Subsequently, referring to FIG.
The schematic configuration of 100 will be described.

Reference numeral 1101 denotes a thermal recording head unit 1100
A support (support plate) for supporting the whole, and a support plate 110
Each unit for controlling the temperature of the thermal recording head unit 1100 is provided on the lower surface side of the unit 1 as described later. 1
Reference numeral 103 denotes a substrate to be bonded on a support plate 1101;
5, 1107, 1109 and 1111 are etched,
An electrothermal transducer (hereinafter referred to as a heater), an electrode, a liquid path wall, and a top plate formed on the substrate 1103 through a semiconductor manufacturing process such as vapor deposition and sputtering. In addition, the common liquid chamber 1115 to the ink ejection port 1113 and the top plate 1111
Are formed at the same time. Reference numeral 1117 denotes an ink supply port formed in the top plate 1111, reference numeral 1119 denotes a supply pipe connection connector, and reference numeral 1121 denotes an ink supply pipe.
5 includes an ink supply pipe 1121 from an ink storage unit (not shown).
Supplies ink in accordance with ink consumption.

Such a thermal recording head unit 1100
In the state described above, the ink is guided from the common liquid chamber 1115 to the ink discharge port 1113 via the liquid path 1123 by capillary action, and a meniscus is formed in the ink at the ink discharge port 1113, so that the ink is in a stable state in preparation for the discharge. Can be kept. Thus, the heater 110
The ink is ejected from the ink ejection port corresponding to the heater driven by the selective driving of the nozzle 5, and the ink 5 flies as an ink droplet for textile printing.

Next, a mechanism for controlling the temperature of the thermal recording head unit 1100 according to the present invention will be described with reference to FIG.

Here, reference numerals 1131 and 1132 denote a head temperature detecting means provided on the back side of the support plate 1101 near the heater 1105 of the thermal recording head unit 1100 and a common liquid chamber 1115 from the heater 1105 also on the back side.
This is a head heating means provided at a suitable position for heating over. The temperature detected by the head temperature detecting means 1131 is sent as an electric signal to the control unit 1133, and based on the detected temperature, the temperature of the thermal recording head unit 1100 is maintained at or above a lower limit in an allowable predetermined temperature range. The head heating means 1132 is driven. Also, 11
34 is a fluid passage provided on the back side of the support plate 1101;
A fluid, for example, water flows through the fluid passage 1134 so as to keep the temperature of the thermal recording head unit 1100 at or below the upper limit value in the above-mentioned predetermined temperature range.

Reference numeral 1135 denotes a fluid (water) in the fluid passage 1134.
1136 is a main tank, 1
Reference numeral 137 denotes a sub-tank in which the water supplied to the fluid passage 1134 is returned. The sub-tank 137 is set so that a head difference of H is maintained between the water stored in the main tank 1136 and the water collected in the sub-tank 1137. ing. Also, 1138
Is a solenoid valve that is interposed in the middle of a circulation pipe 1135 that guides water from the main tank 1136 to the fluid passage 1134, and whose opening and closing are controlled by a control unit 1133, and 1139 is automatically activated when the water level in the sub tank 1137 reaches a predetermined height. For returning water to the main tank 1136
The pump 1139 may function to constantly return an amount corresponding to the circulating amount from the sub tank 1137 to the main tank 1136 during the circulation of water to the fluid passage 1134. 1140A and 1140B are water temperature sensors for detecting the water temperature of the main tank 1136 and the sub tank 1137, respectively, and 1141A and 1141B are water temperature control devices capable of controlling the temperature of the water based on the detected water temperatures from the water temperature sensors 1140A and 1140B, respectively.

The thermal recording head unit 1100 according to this embodiment
As described above, the temperature control mechanism controls the driving of the head heating means 1132 and the solenoid valve 1138 by the control unit 1123 based on the temperature detection (electric) signal from the head temperature detection means 1131. The temperature of the thermal recording head unit 1100 is kept within a predetermined temperature range.

In this embodiment, the unit 1100
Is made of aluminum, and has a much higher thermal conductivity than the top plate 1111 made of glass. Therefore, it is possible to propagate the heat energy remaining on the substrate 1103 during printing mainly to the support plate 1101 and radiate the heat to the outside.

That is, if the heat radiation from the support plate 1101 is not efficiently performed with good responsiveness, the temperature rise of the thermal recording head unit 1100 during printing becomes large and stable recording cannot be performed. ,
Efficiently and effectively removing heat from the support plate 1101 is necessary to maintain the temperature of the thermal recording head unit 1100 within a predetermined temperature range and, as an effect, to perform stable printing.

In the basic configuration example, the thermal recording head unit 11
The reason why water having a relatively large heat transfer coefficient was used as the fluid for controlling the temperature of 00 is as described above. In the basic configuration example, the fluid passage 1134 is provided on the back surface side of the support plate 1101 of the thermal recording head unit 1100 and as close as possible to the heater 1105 in configuration (see FIG. 5A). ). Here, the fluid passage 11
34 itself serves as a wall for securing a flow path of water, and by flowing water directly onto the support plate 1101, heat conduction is improved as much as possible, and the support plate 1101 can be efficiently brought to a desired temperature. The fluid passageway 1134, although intended to ensure the flow path of the water as described above, the configuration is not limited to those described above, may for example thermal conductivity, as shown in FIG. 5 (B) Aluminum Support plate 110 made of Nyum etc.
1 itself to form a fluid passage 1134,
As shown in FIG. 5C, the carriage 10 on the printing apparatus side is used.
10, a fluid passage 1134 is formed, and the thermal recording head unit 1100 is mounted when the thermal recording head unit 1100 is mounted.
It is also possible to arrange so that the outside of the fluid passage 1134 may be in contact with the fluid passage 100.

In FIG. 1, the main tank 1136
By opening the solenoid valve 1138, the water stored in the tank flows in the direction of arrow A due to the head difference H, and is returned from the fluid passage 1134 to the sub tank 1137. In the case of this example, in consideration of the responsiveness of the temperature control, it is preferable that the time difference between the opening and closing of the electromagnetic valve 1138 and the flow of water in the fluid passage 1134 thereby be as short as possible. The outlet of the open circulation pipe 1135 is always located below the water surface, and it is preferable that the circulation pipe 1135 and the fluid passage 1134 are always filled with water regardless of whether the solenoid valve 1138 is opened or closed.

Next, an example of the control operation of the heating means 1132 and the solenoid valve 1138 will be described with reference to FIGS.

FIG. 6A shows the procedure of the control operation of the heating means 1132. When the power supply of the apparatus is turned “ON”, it is first determined in step 101 whether or not there is a heating control request.
If ES), in step 102, the temperature detecting means 1131
Of the temperature data Tn (n = 0 to 3). From this temperature data Tn, it is determined in step 103 whether or not the thermal recording head unit 1100 is lower than a set temperature range.
If it is lower, the process proceeds to step 104, in which the heating means 1132 is driven to heat. If it is determined in step 103 that the temperature is not lower than the set temperature range, the process proceeds to step 105 to determine whether or not the temperature is higher than the set temperature range.
If not, leave it alone. The heating unit 1132 is controlled while repeating the above operation. When it is determined in step 101 that there is no heating control request, the control operation is stopped.

FIG. 6B shows the procedure of the control operation of the solenoid valve 1138. When the power supply of the apparatus is turned "ON", first, at step 301, it is determined whether or not a request for the solenoid valve control is made. If so, the process proceeds to step 302, where the temperature data from the temperature detecting means 1131 is read. Step 303
To determine whether the temperature data is higher than the set temperature range,
If higher, the drive of the solenoid valve 1138 is set to “O” in step 304.
N ". Here, if the temperature is not higher than the set temperature range, the process proceeds to step 305 to determine whether or not the temperature is lower than the set temperature range.
At 6, the solenoid valve 1138 is stopped, and if it is not low, it is left as it is. The above operation procedure is repeated to control the solenoid valve 1138, and when it is determined in step 301 that the control is not necessary, the control operation ends.

As described above, the flow rate of water flowing through the fluid passage 1134 due to the head difference H between the water surface in the main tank 1136 and the water surface in the sub tank 1137,
In addition, since the flow velocity is determined, when setting the head difference H, the flow velocity required for controlling the temperature of the thermal recording head unit 1100 is sufficiently obtained.

The timing for driving the pump 1139 is determined by the main tank 1136 or the sub tank 113.
A sensor such as a residual detection sensor may be attached to the sensor 7 and a signal based on the sensor may be used. Alternatively, the number of opening and closing of the electromagnetic valve 1138 or the time may be determined. Furthermore, in the main tank 1136 and the sub tank 1137,
Water temperature sensors 1140A and 1140B are provided, respectively, and the water temperature control device 1
The respective water temperatures are controlled via 141A and 1141B and are maintained within a predetermined temperature range. Note that, here, the set temperature range of the water to be maintained may be maintained within a certain temperature range regardless of the environment temperature outside the device or inside the device,
For example, when the environmental temperature changes from a ° C. to b
In the case of ° C., the temperature may be controlled by providing a predetermined temperature table for maintaining the water temperature at c ° C. to d ° C.

As described above, by controlling the temperature of the circulating water within a predetermined temperature range, a desired cooling effect is always obtained, and the temperature of the thermal recording head unit 1100 is controlled together with the heating by the heating means 1132. Can be made easier.

Further, the water temperature control devices 1141A, 1141
B, the ink jet recording apparatus (printing means) 1
With respect to a change in the environmental temperature surrounding the 000, the temperature maintenance width of the thermal recording head unit 1100 does not change and recording can always be performed within a stable temperature fluctuation, and as a result, a desired recording quality can be maintained. In particular, in the present basic configuration example, a fluid having a high thermal conductivity, such as water, is used as the fluid for adjusting the temperature of the thermal recording head unit 1100, so that the temperature of the fluid greatly affects the amount of heat transferred . Therefore, it is necessary to control the thermal recording head unit 1100 so that the water temperature does not greatly change according to the environmental temperature.
Is important in maintaining a predetermined temperature range.

In particular, for a head or the like that generates a large amount of heat and has a remarkable temperature rise during a printing operation, setting the water temperature to a lower temperature range allows a cooling effect such that the temperature is controlled to a stable print head temperature range. Can be obtained.

In the basic configuration example, the water temperature sensors 1140A and 1140B and the water temperature control device 11 are provided in both the main tank 1136 and the sub tank 1137.
41A and 1141B, but the main tank 11
These may be provided only in 36 to control the water temperature.

In the basic configuration example shown in FIG. 1, since the water flow path system is a circulation system, the water flow path system (in particular, the circulation pipe 11
35 and the inside of the fluid passage 1134), the flow rate of water flowing through the thermal recording head unit 1100,
It is preferable to use pure water so that the flow rate does not change. Furthermore, it is preferable that the main tank 1136, the sub tank 1137, and the circulating pipe 1135 that constitute the water flow path system be made of a material having a high heat insulating effect so that an external temperature change is not transmitted to water as much as possible.

Reference Example FIG. 7 shows a reference example applied to a serial type ink jet recording apparatus. In this example, the temperature of the water temporarily stored in the main tank 1136 is
The temperature is maintained at a predetermined temperature by the control unit 40 and a water temperature control device 1141 driven and controlled by the detection signal.

In this example, water maintained at a substantially constant temperature in the main tank 1136 is supplied by a pump 1139 in the direction of arrow A, passes through a circulation pipe 1135 and a fluid passage 1134, and is returned to the main tank again. Returned to 1136. Here, the pump 1139 is continuously driven during the printing operation of the ink jet printing apparatus (printing means) 1000 and during the printing operation waiting time before and after the printing operation. As a result, the circulation pipe 1135 and the fluid passage 11
The flow of water flowing through the inside 34 is circulated at a constant flow rate and flow rate during that time, and the conditions of the set temperature, the flow rate, and the flow rate will be described later in detail.

[0037] Incidentally, the fluid passages 1134 in the present reference example,
Similar to the basic configuration example 1, in which the water directly on the support plate 1101 configured to contact, a configuration example of a fluid passage 1134 that is suitable for the present reference example in FIG. 5 (D). As shown in this figure, the support plate 1101 is formed in a concave shape near the heater 1105 toward the heater 1105. this is,
By reducing the heat conduction distance of the support plate 1101, the temperature of water can be efficiently transmitted to the ink in the vicinity of the heater 1105, the substrate 1103, and the ink in the liquid path 1123 with good responsiveness. Is preferably as thin as possible within a range that does not affect the heat conversion efficiency of the heater 1105.

According to the present reference example, the pump and the fluid passage 1134 provided a thermal recording head unit 1100, thereby continuously circulating the water into the fluid passages 1134 1139
And a water temperature control device 11 for constantly maintaining the water at a constant temperature.
41, the thermal recording head unit 1
The thermal recording head unit 1100 can be maintained in a temperature range in which stable recording can be performed without providing a heating unit and a temperature detecting unit in the thermal recording head unit 100.

The following describes the setting of the water temperature and the fluid passage 1
A description will be given by exemplifying the temperature control operation together with the setting conditions of the flow rate and the flow rate of the water circulating in the 134.

Now, the temperature of the substrate 1103 in the vicinity of the heater 1105 of the thermal recording head unit 1100 is set to d.degree.
If the temperature can be maintained at e ° C. (at high temperature), stable ejection and desired recording quality can be obtained. When the thermal recording head unit 1100 is in a recording operation waiting state,
Since the heater 1105 is not energized, the heater 110
Although there is no heat generation from 5, water maintained at a water temperature of (d + f) ° C. (f is a temperature lost by heat transfer) has a flow rate g (m / s) and a flow rate h (1 / min) or more. The temperature in the vicinity of the heater 1105 can be maintained at the low-temperature limit d ° C. even if there is no heating means in the thermal recording head unit 1100.
101 and the heat transfer efficiency between the support plate 1101,
In addition, the value of f decreases as the thermal conductivity of the substrate 1103 increases and the thickness a decreases.

On the other hand, when the thermal recording head unit 1100 is performing a recording operation, the heater 1105 is in a state of being energized, so that the heater 1105 generates heat. In such a recording state, the water having the set water temperature (d + f) ° C. determined during the recording operation waiting state is circulated, and the maximum amount of heat generated from the heater 1105 that can be assumed during recording is represented by i (W). While suppressing heat storage, the heater 1105
In order to maintain the temperature in the vicinity at or below the high temperature limit e ° C. (at or above the low temperature limit d ° C.), the flow rate j (> g) and the flow rate k
(> H) is set as follows.

Graph 1 shown in FIG. 8 shows that, when the amount of heat generated by the heater 1105 changes, the water at the water temperature (d + f) ° C. is circulated, and the flow velocity j and the flow rate k at that time are changed. It shows how the temperature near the heater 1105 of 1100 changes.

In graph 1, when the calorific value of the electrothermal transducer heater is 0 (W), that is, when the recording operation is in a standby state, the temperature of the water set to maintain the temperature of the recording head at d (° C.) is (D + f) ° C. At this set water temperature, if the flow velocity j and the flow rate k of the circulating water are too small, the amount of heat generated from the heater 1105 becomes maximum i as shown by the two-dot chain line.
In the case of (W), the temperature of the thermal recording head unit 1100 cannot be suppressed to e ° C. or less. Therefore, the flow rate j and the flow rate k are gradually increased, and when the flow rate j (> g) and the flow rate k (> h) are exceeded, the heater 11 is increased as shown by the solid line.
The heater 1105 even when the calorific value from 05 is the maximum i
The temperature in the vicinity can be suppressed to e ° C.

The flow velocity J (> g) and the flow rate K at this limit
(> H), even when the amount of heat generated from the heater 1105 is 0, water is circulated at the above conditions, the flow rate g and the flow rate h or more.
Can be kept. Further, by further increasing the flow velocity j and the flow rate k as indicated by the broken lines, the temperature of the recording head can be maintained within a more stable temperature range.

As described above, by setting the water temperature, the flow rate, and the flow rate, all changes in the calorific value from the time when the calorific value is 0 to the maximum when the calorific value is i (W) are obtained.
The temperature in the vicinity of the electrothermal conversion pair 202 can be maintained in the range of dC to eC.

However, what has been described above is based on the assumption that the water temperature can be maintained at (d + f) ° C. without any temperature change. Actually, the water temperature is always maintained at (d + f) ° C. without any temperature change. It is not easy to maintain.

Now, it is assumed that the water temperature cannot be always maintained at (d + f) ° C., but changes within ± X ° C. In this case, if the water temperature, the flow rate, and the flow rate are set as described above, when the heating value is 0 (W) and the water temperature is (d + f−X) ° C. as shown in a graph 2 in FIG. When the temperature of the head becomes d−x ° C. as indicated by a broken line and is supercooled, and when the calorific value is i (W), the recording is performed when the water temperature is (d + f + X) ° C. as indicated by a two-dot chain line. The temperature of the head becomes e + x ° C., which means that the cooling capacity is insufficient.

Therefore, the recording head temperature is always set at d ° C. to e ° C.
In order to maintain the water temperature, it is necessary to determine the set water temperature value, the flow rate, and the flow rate in consideration of the change in the water temperature (± X ° C.) as shown in a graph 3 in FIG. That is, when the heating value is 0, the heater 1 of the thermal recording head unit 1100
The water temperature at which the temperature near 105 is maintained at d ° C is (d + f−
X) ° C., the water temperature (d +
At (f + X) ° C., as shown by the two-dot chain line in the graph 3, when the heat generation amount is the maximum i ° C., the flow rate and the flow rate are set such that the temperature near the heater 1105 of the thermal recording head unit 1100 can be maintained at e ° C. or less. .

As described above, by determining the water temperature, the flow rate, and the flow rate, even if the water temperature changes within ± X ° C. with respect to the water temperature set value (d + f) ° C., all the heat values 0 to i (W The temperature in the vicinity of the heater 1105 in the thermal recording head unit 1100 can be maintained in the range of d ° C. to e ° C. with respect to the change of (d).

Although the flow velocity and the flow rate have been described in the same manner so far, this is because the fluid passage 1134 and the flow path
This is because the flow velocity is proportional to the flow rate if the cross-sectional area of the entire flow path determined thereby is fixed.

However, in the actual heat transfer, if the area of the cooling surface is the same, the flow velocity is affected. Therefore, the flow rate is reduced so that a large flow velocity can be obtained (by flowing a small amount of water). Fluid passage 11 so that a large heat transfer effect is obtained)
34 need to be determined.

For example, if the fluid passage 1134 is made of a material having extremely low thermal conductivity in the above-described FIG. 5D, if the heat in the support plate 1101 is transferred to water, Since only the contact surface between the water and the support plate 1101 does not directly affect the other contact area between the water and the fluid passage 1134, the fluid passage 1134 is secured while maintaining a desired flow velocity.
, The flow rate of water used for temperature control can be reduced by lowering the height (h) of the above and reducing the cross-sectional area of the flow path of water.

[0053] As described above, according to the reference example, without providing the heating means and the temperature detecting means to heat the recording head unit 1100, the temperature recorded stably the temperature of the heater 1105 near the thermal recording head unit 1100 is performed Can be maintained within the range.

[ Basic Configuration Example 2 ] FIG. 11 shows a basic configuration example 2 applied to a serial type ink jet recording apparatus (printing means) 1000.

This example of the basic configuration is based on the thermal recording head unit 1.
Subsequent to the detection signal of the temperature detecting means (not shown) attached to 100, a heating means (not shown) and an electromagnetic valve 1208 for controlling the ejection of gas compressed to at least 1 atm or more are provided. By performing ON / OFF control, the temperature in the vicinity of the heater 1105 of the thermal recording head unit 1100 is maintained within a temperature range in which stable recording can be performed.

Here, the gas (for example, air) is compressed by the air compressor 1201 and the air temperature controller 1203
After the temperature is controlled to a desired temperature, the air is sprayed from an air nozzle (not shown) into a fluid passage 1204 provided in the support plate 1101. 1205 is a compressed air supply pipe. In addition,
As the air temperature control device 1203, a known air cooling device may be used, or a spiral pipe made of metal (not shown) having good heat conductivity is provided around the pipe, and air compressed through water in the pipe is provided. May be cooled to a desired temperature or lower. The compressed air is supplied from the air nozzle to the support plate 110 of the thermal recording head unit 1100.
When the air is injected toward the air compressor 1, the air is released to the atmospheric pressure, and the temperature of the injected air is lower than the temperature of the air compressed by the air compressor 1201 due to the effect of the adiabatic expansion that occurs at that time.

The present basic configuration example has an effect of the adiabatic expansion described above, and furthermore, by providing a gas temperature control unit, a thermal recording head that generates a larger amount of heat than a conventional temperature control method using a blower or the like. Temperature control capability is high,
The influence of the environmental temperature outside the device is small.

[ Embodiment ] The temperature control of the thermal recording head according to the present embodiment is performed by controlling the fluid passage provided in contact with the thermal recording head and keeping the fluid in the fluid passage constant.
Cools the thermal recording head by circulating at the flow velocity of
This is performed by providing a cooling means, a temperature control means for controlling the temperature of the fluid, and a drive control means for the thermal recording head which supplies electric power to the extent that the ink does not foam even in the heater for which the print signal is OFF.

That is, as described in Japanese Patent Application Laid-Open No. 4-47948, by giving power energy to the heater whose print signal is OFF to such an extent that the heater does not foam, a print standby state or a recording duty is provided. Instead of the thermal recording head having a constant amount of heat storage per unit time of the recording head, a fluid controlled at a constant temperature and a constant flow rate is continuously supplied to a fluid passage provided in contact with the thermal recording head. Then, by removing a certain amount of heat per unit time from the thermal recording head, the temperature of the thermal recording head is maintained at a desired temperature at which stable ejection can be performed.

For example, assuming that the heat storage amount of the thermal recording head per unit time is constant and the flow velocity of the fluid continuously flowing in the fluid passage provided in contact with the thermal recording head is constant, FIG.
As shown in (A), the temperature of the thermal recording head is maintained at a specific temperature β ° C. corresponding to the fluid control temperature α ° C.

However, when the thermal recording head is actually affected by the environmental temperature surrounding the apparatus or when the thermal recording head is replaced,
Alternatively, in the case of a liquid ejecting apparatus that performs color printing using a plurality of thermal recording heads, a slight individual difference (including an individual difference of a fluid passage) in manufacturing a heat transfer structure and a heat radiation structure for each thermal recording head. The temperature of the thermal recording head does not always become β ° C with respect to the fluid control temperature α ° C due to the difference in heat transfer capability and heat radiation capability, etc., and depends on the temperature around the apparatus or every time the thermal recording head is replaced. In addition, there arises a problem that the print density changes and the color balance changes.

For example, FIG. 12A is a graph showing the control temperature of the fluid flowing through the fluid passage provided in contact with the thermal recording head, and the temperature maintained by the thermal recording head corresponding to the control temperature of each fluid. In the graph, the thermal recording head is maintained at β ° C. with respect to the fluid control temperature α ° C. when the specific thermal recording head is under a specific environmental temperature and the environmental temperature changes. Then, the head temperature is not necessarily maintained at β ° C. This is because the maintenance temperature of the head has a slight influence not only on the heat transfer ability of the fluid flowing in the fluid passage, but also on the natural heat radiation from other parts of the thermal recording head where the temperature control fluid is not flowing. Because.

FIG. 1 is a graph showing the control temperature of the fluid flowing through the fluid passage provided in contact with the thermal recording head and the temperature maintained by the thermal recording head corresponding to the control temperature of each fluid.
In the graph of FIG. 2 (B), as indicated by H1, H2, h3, and H4, it is an individual difference in manufacturing for each thermal recording head,
Assuming that the heat transfer capacity and the heat dissipation capacity are different, even if the control temperature of the fluid is set to α1 ° C., the temperature of the thermal recording head is
The temperature that can be maintained, such as β1 ° C. to β4 ° C., changes according to individual differences in heads.

In order to keep the temperature of the thermal recording head at a desired temperature at all times, the liquid ejecting apparatus according to the present invention includes a temperature detecting means for detecting the temperature of the thermal recording head. A means for controlling the temperature of the flowing fluid for each thermal recording head based on the detection signal of the temperature detecting means.

For example, when it is now desired to always maintain the working temperature of the thermal recording head at β1 ° C., in the graph of FIG.
Α1 for each of H1, H2, H3 and H4
By setting and controlling the temperature of the fluid at a temperature of ° C, α2 ° C, α3 ° C, and α4 ° C, the temperature of the thermal recording head can be maintained at a desired temperature β1 ° C for all the heads (H1 to H4).

That is, when the head temperature detected by the temperature detecting means is lower than the desired temperature, the control temperature of the fluid is set higher, and when the head temperature is higher, the fluid is controlled to a lower temperature. In the temperature control method of the thermal recording head according to the present embodiment in which the fluid is continuously supplied to the recording medium, the above problem can be solved and a stable working temperature can be maintained.

At this time, by using a heating means provided separately from the heater for ink ejection in the thermal recording head unit and applying auxiliary heating, it is possible to more easily control the temperature of the thermal recording head with high stability. .

The graph of FIG. 13A shows that the heating means is provided in the thermal recording head (H4) in the graph of FIG. 12B, and when the temperature of the thermal recording head is β1 ° C. or less, the heating means is turned off. 9 is a graph showing the relationship between the control temperature of the fluid and the temperature at which the thermal recording head is maintained at each fluid temperature when the control of heating ON and heating OFF at β1 ° C. or higher is performed.

If the heating means is not driven, the fluid is α4
When the temperature is controlled at a temperature lower than 0 ° C., supercooling occurs and the thermal recording head cannot be maintained at a desired temperature β1 ° C. (broken line in the graph).
On the other hand, when the heating means is driven, the characteristics as shown by the solid line in the graph are exhibited.

In the solid line of the graph, the control temperature of the fluid is α
In the region higher than 4 ° C., the temperature of the thermal recording head is higher than β1 ° C., and the desired thermal recording head maintaining temperature β1 ° C. cannot be maintained.

In the solid line of the graph, the control temperature of the fluid is α
In a region lower than 4 ° C. and higher than α4 ′ ° C., the temperature of the thermal recording head is maintained at β1 ° C. while the driving of the heating means is turned ON and OFF.

For example, if the heating means is not driven when the control temperature of the fluid is α4 ′ ° C., the temperature of the thermal recording head becomes
The balance between the amount of heat stored per unit time of the thermal recording head and the amount of heat taken per unit time by the fluid temperature-controlled to α4 ′ ° C flowing in the fluid passage provided in contact with the thermal recording head is β1 ′ ° C. On the other hand, the temperature of the thermal recording head is raised to β1 ° C. by adding driving of the heating means and adding a supplementary amount of heat.

In the graph, the control temperature of the fluid is α
In the region lower than 4 ° C., the temperature of the thermal recording head is β1 ° C.
Lower temperature. At this time, the value of α4 ′ ° C. depends on the heating capacity of the heating means, and the temperature of the thermal recording head can be raised to β1 ° C. even with a fluid having a lower control temperature by using a heating means having a large heating capacity. Become like

The graph of FIG. 13B shows the thermal recording heads H having different heat transfer and heat radiating capacities in FIG. 12A.
Α4 ′ ° C. at 1, H2, H3 and H4 (FIG. 13
(A)) = When the heating means having the ability to satisfy α1 ° C. (FIG. 12B) is driven, the control temperature of the fluid and the temperature of the thermal recording head are stable at the control temperature of each fluid. This is a graph showing the temperature at which the temperature of the fluid is controlled to α1 ° C. by driving the heating means having the above-mentioned ability.
This indicates that the temperature of the thermal recording head can be controlled and maintained at β1 ° C., which is the desired temperature, at H4 to H4.

Similarly, when the temperature of the thermal recording head is equal to or lower than the desired temperature β1 ° C., the heating O
At the time of N, β1 ° C or more, the control of heating OFF is performed.
By providing auxiliary heat to a thermal recording head, a recording apparatus capable of constantly performing recording at a desired thermal recording head temperature even when the temperature of an environment surrounding the apparatus changes is provided. be able to.

As described above, the ink jet recording apparatus according to the present embodiment has a means for keeping the heat storage amount of the thermal recording head per unit time constant and a means for keeping the heat amount taken from the thermal recording head per unit time constant. Means for continuously feeding fluid into a fluid passage provided in contact with the thermal recording head, and control means for controlling the temperature of the fluid to a desired temperature. Is provided with a heating means, and by applying supplementary heating, the temperature of the thermal recording head is constantly stabilized without being affected by the environmental temperature surrounding the apparatus and various individual differences of the thermal recording head. The recording quality and the recording density can be maintained at a specific temperature at which the recording quality can be obtained.

In the embodiment described above, it is assumed that the temperature control of the thermal recording head having a large heat value is performed.
Although the thermal recording head of the serial type inkjet recording device used in the textile printing device has been described above as an example, the application of the present invention is not limited to the above, and the size of the device, the number of thermal recording head units The present invention can be widely applied to a liquid ejecting apparatus that needs to control its temperature, regardless of the type or the form.

[0078]

As described above, according to the present invention,
A heater for discharging ink is driven by a print signal to
Heater that discharges ink and print signal is OFF
To the drive by supplying enough power not to eject ink.
Movement to control recording by the recording head.
Drive control means and the heater of the substrate are formed.
Fluid into the fluid passage on the opposite side of the
Cooling the recording head by circulating it at a flow rate
Cooling means, temperature control means for controlling the temperature of the fluid, temperature detection means for detecting the temperature of the recording head,
Along with the control by the drive control means, the temperature control means
Using the fluid controlled to a predetermined temperature by a step,
The cooling means is controlled to cool the recording head.
Control means, the control means comprising:
Means according to the temperature of the recording head detected by the means.
The control temperature of the fluid is changed by the temperature control means.
And heating means in the thermal recording head unit.
Equipment and remove the equipment by applying supplementary heating.
Influenced by winding environment and various individual differences of thermal recording head
Without changing the temperature of the thermal recording head
At a specific temperature at which the recording quality and recording density can be obtained .

It should be noted that even in a liquid ejecting apparatus using a recording head unit that generates a large amount of heat, it is possible to suppress the temperature rise of the thermal recording head during recording and obtain stable recording quality.

[0080]

[0081]

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a temperature control device of a thermal recording head unit according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing an outline of an inkjet textile printing apparatus to which the present invention can be applied.

FIG. 3 is a perspective view showing an outline of the ink jet textile printing apparatus shown in FIG.

FIG. 4 is a partially broken perspective view showing a configuration of a thermal recording head unit applied to the present invention.

FIGS. 5A to 5D are cross-sectional views illustrating examples of the configuration of a thermal recording head unit according to the present invention, in four examples of FIGS.

FIG. 6 is a flowchart showing an example of the operation sequence of the heating means and the solenoid valve according to the present invention by (A) and (B).

FIG. 7 is a configuration diagram of a temperature control device of a thermal recording head unit according to a second embodiment of the present invention.

FIG. 8 is a graph 1 of a characteristic curve showing a temperature change of a thermal recording head unit when a flow rate and a flow rate are changed with respect to a change in a calorific value of an electrothermal transducer in Example 2.

FIG. 9 is a graph 2 showing, as a characteristic curve, a change in the temperature of the thermal recording head unit when the water temperature is changed with respect to a change in the amount of heat generated by the electrothermal converter in Example 2.

FIG. 10 is a graph 3 showing, as a characteristic curve, a change in temperature of the thermal recording head unit different from that in FIG. 9 with respect to a change in the amount of heat generated by the electrothermal transducer in Example 2.

FIG. 11 is a configuration diagram of a temperature control device of a thermal recording head unit according to a third embodiment of the present invention.

FIG. 12 is a diagram illustrating temperature control of a thermal recording head according to Example 4 of the present invention as characteristic curves (A) and (B).

FIG. 13 is a diagram showing temperature control of a thermal recording head according to Example 4 of the present invention as characteristic curves (A) and (B).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cloth (recording material) 11 Unwinding roller 13, 15, 17, 19 Roller 21 Winding roller 100 Conveying means 1000 Printing means 1010 Head carriage 1100 Thermal recording head unit 1101 Support plate 1103 Substrate 1105 Electrothermal converter (heater) 1113 Ink ejection port 1115 Common liquid chamber 1123 Liquid path 1131 Head temperature detecting means 1132 Head heating means 1133 Control unit 1134 Fluid path 1135 Circulation pipe 1136 Main tank 1137 Sub tank 1138 Electromagnetic valve 1139 Pump 1140A, 1140B Water temperature sensor 1141A, 1141B Water temperature control device 1201 Air compressor 1203 Air temperature control device 1205 Compressed air supply pipe 1208 Solenoid valve

Continuation of the front page (56) References JP-A-3-166954 (JP, A) JP-A-1-242257 (JP, A) JP-A-63-41153 (JP, A) JP-A-6-24927 (JP) , U) (58) Field surveyed (Int. Cl. ⁷ , DB name) B41J 2/01 B41J 2/175 B29C 47/92

Claims (3)

(57) [Claims] An electric power is supplied to a heater formed on a substrate to drive the heater.
In using the heat energy generated by dynamic
Using a print head that discharges ink
In an ink jet recording apparatus that performs recording by discharging ink, a heater that discharges ink in response to a print signal is driven to drive the ink.
Heater that discharges ink and print signal is OFF
To the drive by supplying enough power not to eject ink.
Movement to control recording by the recording head.
Drive control means, and a surface of the substrate opposite to the surface on which the heater is formed.
The fluid is circulated at a constant flow rate through the fluid passage provided in
And cooling means for cooling the recording head with Rukoto, a temperature control means for controlling the temperature of said fluid, a temperature detecting means for detecting a temperature of the recording head, together with the control by the drive control means, said temperature control hand
Using the fluid controlled to a predetermined temperature by a step,
The cooling means is controlled to cool the recording head.
Control means , wherein the control means detects the temperature detected by the temperature detection means.
According to the temperature of the recording head, the temperature control means
Ink cartridge characterized by changing the control temperature of the fluid
Jet recorder . 2. The method according to claim 1, wherein a plurality of said recording heads are used.
The control means may include the temperature control means for each of the recording heads.
Controlling the temperature of the fluid by
Item 2. An ink jet recording apparatus according to item 1. Wherein the fluid jet recording apparatus according to claim 1 or 2, characterized in that is water.