JP7370287B2 - Inkjet printers and inkjet printer control methods - Google Patents

Description

The present invention relates to an inkjet printer that prints by ejecting ink. The present invention also relates to a method of controlling such an inkjet printer.

2. Description of the Related Art Inkjet printers that include an inkjet head that ejects UV ink, which is an ultraviolet curable ink, are conventionally known (for example, see Patent Document 1). The inkjet printer described in Patent Document 1 includes an extra-head ink heating device that warms ink supplied to the inkjet head outside the inkjet head. The inkjet head is formed with a plurality of nozzles that eject ink. Further, inside the inkjet head, a plurality of ink channels are formed to which a plurality of nozzles are connected. For example, an inkjet head is formed with four ink channels through which color inks of different colors flow. The inkjet head includes a drive unit that ejects ink from a plurality of nozzles.

In the inkjet printer described in Patent Document 1, a film-shaped heater for warming ink ejected from a plurality of nozzles to reduce the viscosity of the ink is wrapped around the outer periphery of an inkjet head. The inkjet head is equipped with a temperature sensor for detecting the temperature of ink in the ink flow path. The temperature sensor is placed inside the inkjet head. The heater is controlled based on the temperature detected by the temperature sensor.

Japanese Patent Application Publication No. 2015-168243

The inventor of the present application has investigated that in an inkjet printer in which a plurality of ink channels are formed in an inkjet head, such as the inkjet printer described in Patent Document 1, the print quality may deteriorate depending on the printing conditions. revealed by.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an inkjet printer equipped with an inkjet head in which a plurality of ink channels are formed, which can suppress deterioration in print quality regardless of printing conditions. It is in. Another object of the present invention is to control a method for controlling an inkjet printer, which makes it possible to suppress deterioration in print quality regardless of printing conditions in an inkjet printer equipped with an inkjet head in which a plurality of ink channels are formed. Our goal is to provide the following.

In order to solve the above problems, the inventor of the present application conducted various studies. As a result, the inventor of the present application first found that in an inkjet printer in which a plurality of ink channels are formed in an inkjet head, UV ink, in particular, has a high viscosity at room temperature and changes in viscosity with temperature fluctuations. It has been discovered that when printing is performed using ink with a large amount of ink, the print quality tends to deteriorate depending on the printing conditions. In addition, the inventor of the present invention has proposed that when printing is performed using ink that has a high viscosity at room temperature and whose viscosity fluctuates greatly with temperature fluctuations in an inkjet printer in which a plurality of ink channels are formed in the inkjet head. However, it has been found that if the ink supplied to the inkjet head cannot be sufficiently heated, the print quality is more likely to deteriorate.

Furthermore, through further study, the inventor of the present application found that in an inkjet printer in which a plurality of ink channels are formed in an inkjet head, for example, due to variations in the amount of ink flowing into each of the plurality of ink channels, If the temperature of the ink in the ink flow path varies depending on the ink flow path, the viscosity of the ink ejected from multiple nozzles will also vary depending on the ink flow path. It has been found that the ink flow path causes variations in the amount and speed of ink ejected from a plurality of nozzles, resulting in deterioration of print quality.

The inkjet printer of the present invention is based on this new knowledge, and in an inkjet printer that prints by ejecting ink, a plurality of nozzles that eject ink and a plurality of ink channels connecting the plurality of nozzles are formed. The inkjet head includes a plurality of ejection energy generating elements that eject ink from each of a plurality of nozzles. The controller controls the flow rate of the plurality of ink channels based on the ink flow rate, which is the flow rate of ink flowing into each of the plurality of ink channels, and the first temperature, which is the temperature inside or outside the inkjet head. In addition to estimating the ink temperature in each, the drive voltage applied to the plurality of ejection energy generating elements is controlled based on the estimation result , and the plurality of ink flow paths is controlled based on the print data input to the control unit. The method is characterized in that the ink flow rate in each of the ink flow rates is specified, and the external temperature detected by the external temperature sensor is set as the first temperature .

Further, the inkjet printer control method of the present invention is based on the above-mentioned new knowledge, and includes an inkjet head in which a plurality of nozzles for ejecting ink and a plurality of ink flow paths connecting the plurality of nozzles are formed. , a method for controlling an inkjet printer, wherein the inkjet head includes a plurality of ejection energy generating elements that eject ink from each of a plurality of nozzles , the inkjet printer includes an external temperature sensor that detects an external temperature of the inkjet printer, In an inkjet printer control method, a plurality of ink channels are controlled based on an ink flow rate, which is the flow rate of ink flowing into each of the plurality of ink channels, and a first temperature, which is the temperature inside or outside the inkjet head. In addition to estimating the ink temperature in each of the plurality of ink flow paths, the drive voltage applied to the plurality of ejection energy generating elements is controlled based on the estimation result , and the drive voltage applied to each of the plurality of ink flow paths is controlled based on the input print data. The present invention is characterized in that the ink flow rate is specified and the external temperature detected by the external temperature sensor is set as the first temperature .

In the present invention, the ink in each of the plurality of ink channels is determined based on the ink flow rate, which is the flow rate of ink flowing into each of the plurality of ink channels, and the first temperature, which is the temperature inside or outside the inkjet head. The temperature of the ejection energy generating element is estimated, and the drive voltage applied to the plurality of ejection energy generating elements is controlled based on the estimation result. Therefore, in the present invention, for example, due to variations in the flow rate of ink flowing into each of the plurality of ink channels, the temperature of the ink in the plurality of ink channels varies depending on the ink channel, and as a result, the temperature of the ink in the plurality of ink channels varies. Even if the viscosity of the ink ejected from the nozzles varies depending on the ink flow path, the amount and speed of ink ejected from the multiple nozzles can be adjusted based on the estimation results of the ink temperature in each of the multiple ink flow paths. It becomes possible to control the drive voltages applied to the plurality of ejection energy generating elements so that variations depending on the path are suppressed. Therefore, in the present invention, it is possible to suppress deterioration in print quality regardless of printing conditions.

Note that the term "driving voltage" in this specification includes not only the driving voltage when the ejection energy generating element is voltage controlled, but also the effective voltage when the ejection energy generating element is PWM (Pulse Width Modulation) controlled. It is.

Further, in the present invention, the inkjet printer includes an external temperature sensor that detects the external temperature of the inkjet printer , and specifies the ink flow rate in each of the plurality of ink flow paths based on input print data, and also determines the external temperature. Since the external temperature detected by the sensor is used as the first temperature, it becomes possible to obtain the ink flow rate and the first temperature relatively easily while simplifying the mechanical configuration of the inkjet printer.

Further, the inkjet printer of the present invention is based on the above-mentioned new knowledge, and in an inkjet printer that prints by discharging ink, a plurality of nozzles for discharging ink and a plurality of ink flow paths connecting the plurality of nozzles are provided. an inkjet head in which a Estimating the temperature of the ink in each of the plurality of ink channels based on the ink flow rate, which is the flow rate of the ink flowing into each of the channels, and the first temperature, which is the temperature inside or outside the inkjet head, and Based on the estimation results, drive voltages applied to the plurality of ejection energy generating elements are controlled, and ink temperatures in each of the plurality of ink flow paths are measured in advance in accordance with various ink flow rates and first temperatures. At the same time, the measurement results are stored in advance in the control unit, and the control unit estimates the temperature of the ink in each of the plurality of ink flow paths based on the measurement results stored in the control unit, the ink flow rate, and the first temperature. It is characterized by
In the present invention, the ink in each of the plurality of ink channels is determined based on the ink flow rate, which is the flow rate of ink flowing into each of the plurality of ink channels, and the first temperature, which is the temperature inside or outside the inkjet head. The temperature of the ejection energy generating element is estimated, and the drive voltage applied to the plurality of ejection energy generating elements is controlled based on the estimation result. Therefore, in the present invention, for example, due to variations in the flow rate of ink flowing into each of the plurality of ink channels, the temperature of the ink in the plurality of ink channels varies depending on the ink channel, and as a result, the temperature of the ink in the plurality of ink channels varies. Even if the viscosity of the ink ejected from the nozzles varies depending on the ink flow path, the amount and speed of ink ejected from the multiple nozzles can be adjusted based on the estimation results of the ink temperature in each of the multiple ink flow paths. It becomes possible to control the drive voltages applied to the plurality of ejection energy generating elements so that variations depending on the path are suppressed. Therefore, in the present invention, it is possible to suppress deterioration in print quality regardless of printing conditions.
Further, in the present invention, the temperature of the ink in each of the plurality of ink flow paths is measured in advance according to various ink flow rates and first temperatures, and the measurement results are stored in the control unit in advance, and the control unit Estimating the temperature of the ink in each of the plurality of ink flow paths in order to estimate the temperature of the ink in each of the plurality of ink flow paths based on the measurement results stored in the control unit, the ink flow rate, and the first temperature. It becomes possible to simplify the processing of the control unit when
In the present invention, for example, an inkjet head includes an in-head heater that heats ink inside the inkjet head, and a target heating temperature of the ink heated by the in-head heater, various ink flow rates, and a first temperature. The temperature of the ink in each of the plurality of ink flow paths is measured in advance, and the measurement results are stored in the control section in advance.

Furthermore, the inkjet printer of the present invention is based on the above-mentioned new knowledge, and in an inkjet printer that prints by ejecting ink, a plurality of nozzles that eject ink and a plurality of ink flow paths connecting the plurality of nozzles are provided. The ink heating mechanism includes an inkjet head in which an ink is formed, an ink heating mechanism that warms ink supplied to the inkjet head, and a control unit that controls the inkjet printer. Each of the plurality of heating mechanism ink channels includes a block-shaped heating unit main body in which a flow path is formed, and a heater outside the head that heats the heating unit main body. The inkjet head includes a plurality of ejection energy generating elements that eject ink from each of the plurality of nozzles, and an in-head heater that heats the ink inside the inkjet head. Estimating the temperature of the ink in each of the plurality of ink channels based on the ink flow rate, which is the flow rate of the ink flowing into each of the ink channels, and the first temperature, which is the temperature inside or outside the inkjet head. , the drive voltage applied to the plurality of ejection energy generating elements is controlled based on the estimation results.
In the present invention, the ink in each of the plurality of ink channels is determined based on the ink flow rate, which is the flow rate of ink flowing into each of the plurality of ink channels, and the first temperature, which is the temperature inside or outside the inkjet head. The temperature of the ejection energy generating element is estimated, and the drive voltage applied to the plurality of ejection energy generating elements is controlled based on the estimation result. Therefore, in the present invention, for example, due to variations in the flow rate of ink flowing into each of the plurality of ink channels, the temperature of the ink in the plurality of ink channels varies depending on the ink channel, and as a result, the temperature of the ink in the plurality of ink channels varies. Even if the viscosity of the ink ejected from the nozzles varies depending on the ink flow path, the amount and speed of ink ejected from the multiple nozzles can be adjusted based on the estimation results of the ink temperature in each of the multiple ink flow paths. It becomes possible to control the drive voltages applied to the plurality of ejection energy generating elements so that variations depending on the path are suppressed. Therefore, in the present invention, it is possible to suppress deterioration in print quality regardless of printing conditions.
Further, in the present invention, the inkjet printer includes an ink warming mechanism that warms ink supplied to the inkjet head, and the ink warming mechanism is a block in which a plurality of heating mechanisms and ink channels through which the ink flows are formed. The inkjet head includes a shaped heating unit main body and an external heater for heating the heating unit main body, each of the plurality of heating mechanism ink channels is connected to each of the plurality of ink channels, and the inkjet head has Since the inkjet head is equipped with an in-head heater that heats the ink inside the head, there are variations in the length and cross-sectional area of the ink flow path of the multiple heating mechanisms, and variations in the ink flow path of the multiple heating mechanisms. Due to variations in the distance between each of the ink channels and the heater outside the head depending on the heating mechanism ink flow path, and variations in the distance between each of the multiple ink flow paths and the heater inside the head due to the ink flow path, The temperature of the ink tends to vary depending on the ink flow path. However, in the present invention, even if the temperature of the ink in the plurality of ink channels varies depending on the ink channels, variations in the amount and speed of ink ejection from the plurality of nozzles depending on the ink channels are suppressed. It becomes possible to control the drive voltage applied to the plurality of ejection energy generating elements.

Further, the inkjet printer of the present invention is based on the above-mentioned new knowledge, and in an inkjet printer that prints by discharging ink, a plurality of nozzles for discharging ink and a plurality of ink flow paths connecting the plurality of nozzles are provided. an inkjet head in which a The ink heating mechanism includes a block-shaped heating unit main body in which a plurality of heating mechanism ink channels through which ink flows are formed, and an external head heater that heats the heating unit main body. each of the plurality of heating mechanism ink channels is connected to each of the plurality of ink channels, and the inkjet head includes a plurality of ejection energy generating elements that eject ink from each of the plurality of nozzles ; The inkjet head includes an in-head heater that heats ink inside the inkjet head , and the control unit controls drive voltages applied to the plurality of ejection energy generating elements based on detection results of the plurality of ink temperature sensors. Features.

Further, the inkjet printer control method of the present invention is based on the above-mentioned new findings, and includes an inkjet head in which a plurality of nozzles that eject ink and a plurality of ink flow paths connecting the plurality of nozzles are formed; The ink heating mechanism includes a plurality of ink temperature sensors for detecting the temperature of ink in each of the plurality of ink flow paths and an ink heating mechanism that warms the ink supplied to the inkjet head. The heating mechanism includes a block-shaped heating unit main body in which an ink flow path is formed inside, and a heater outside the head that heats the heating unit main body. The inkjet printer is connected to each of the ink flow paths, and the inkjet head includes a plurality of ejection energy generating elements that eject ink from each of the plurality of nozzles , and an in-head heater that heats the ink inside the inkjet head. This control method is characterized by controlling drive voltages applied to a plurality of ejection energy generating elements based on detection results from a plurality of ink temperature sensors.

In the present invention, the driving voltages applied to the plurality of ejection energy generating elements are controlled based on the detection results of the plurality of ink temperature sensors for detecting the temperature of ink in each of the plurality of ink flow paths. Therefore, in the present invention, for example, due to variations in the flow rate of ink flowing into each of the plurality of ink channels, the temperature of the ink in the plurality of ink channels varies depending on the ink channel, and as a result, the temperature of the ink in the plurality of ink channels varies. Even if the viscosity of the ink ejected from the nozzles varies depending on the ink flow path, variations in the amount and speed of ink ejected from the multiple nozzles depending on the ink flow path are suppressed based on the detection results of multiple ink temperature sensors. Thus, it becomes possible to control the drive voltage applied to the plurality of ejection energy generating elements. Therefore, in the present invention, it is possible to suppress deterioration in print quality regardless of printing conditions.
Further, in the present invention, the inkjet printer includes an ink warming mechanism that warms ink supplied to the inkjet head, and the ink warming mechanism is a block in which a plurality of heating mechanisms and ink channels through which the ink flows are formed. The inkjet head includes a shaped heating unit main body and an external heater for heating the heating unit main body, each of the plurality of heating mechanism ink channels is connected to each of the plurality of ink channels, and the inkjet head has Since the inkjet head is equipped with an in-head heater that heats the ink inside the head, there are variations in the length and cross-sectional area of the ink flow path of the multiple heating mechanisms, and variations in the ink flow path of the multiple heating mechanisms. Due to variations in the distance between each of the ink channels and the heater outside the head depending on the heating mechanism ink flow path, and variations in the distance between each of the multiple ink flow paths and the heater inside the head due to the ink flow path, The temperature of the ink tends to vary depending on the ink flow path. However, in the present invention, even if the temperature of the ink in the plurality of ink channels varies depending on the ink channels, variations in the amount and speed of ink ejection from the plurality of nozzles depending on the ink channels are suppressed. It becomes possible to control the drive voltage applied to the plurality of ejection energy generating elements.

In the present invention, it is preferable that the ink temperature sensor is disposed near each of the plurality of ink channels or in each of the plurality of ink channels. With this configuration, it becomes possible to accurately detect the temperature of ink in each of the plurality of ink flow paths using the plurality of ink temperature sensors.

As described above, in the present invention, in an inkjet printer equipped with an inkjet head in which a plurality of ink channels are formed, it is possible to suppress deterioration in print quality regardless of printing conditions.

1 is a perspective view of an inkjet printer according to an embodiment of the present invention. 2 is a schematic diagram for explaining the configuration of the inkjet printer shown in FIG. 1. FIG. FIG. 3 is a perspective view of a portion of the peripheral portion of the carriage shown in FIG. 2; 2 is a block diagram for explaining the configuration of the inkjet printer shown in FIG. 1. FIG. 3 is a cross-sectional view for explaining the schematic configuration of the inkjet head shown in FIG. 2. FIG. 3 is a bottom view for explaining the schematic configuration of the inkjet head shown in FIG. 2. FIG. FIG. 4 is a cross-sectional view for explaining the configuration of the heating section main body shown in FIG. 3. FIG. FIG. 5 is a diagram for explaining an example of measurement results of ink temperature in each ink flow path, which are stored in the control unit shown in FIG. 4; 5 is a diagram for explaining an example of a table stored in the control unit shown in FIG. 4. FIG.

Embodiments of the present invention will be described below with reference to the drawings.

(Inkjet printer configuration)
FIG. 1 is a perspective view of an inkjet printer 1 according to an embodiment of the invention. FIG. 2 is a schematic diagram for explaining the configuration of the inkjet printer 1 shown in FIG. 1. As shown in FIG. FIG. 3 is a partial perspective view of the peripheral portion of the carriage 4 shown in FIG. 2. As shown in FIG. FIG. 4 is a block diagram for explaining the configuration of the inkjet printer 1 shown in FIG. 1. As shown in FIG. FIG. 5 is a cross-sectional view for explaining the schematic configuration of the inkjet head 3 shown in FIG. 2. As shown in FIG. FIG. 6 is a bottom view for explaining the schematic configuration of the inkjet head 3 shown in FIG. 2. FIG. 7 is a cross-sectional view for explaining the configuration of the heating section main body 20 shown in FIG. 3. FIG.

The inkjet printer 1 of this embodiment (hereinafter referred to as "printer 1") is, for example, a commercial inkjet printer, and prints on the print medium 2 by ejecting ink. The printer 1 uses ink that has a high viscosity at room temperature and whose viscosity fluctuates greatly with temperature fluctuations. In this embodiment, the printer 1 uses UV ink that is an ultraviolet curable ink. The printing medium 2 is, for example, printing paper, cloth, or a resin film.

The printer 1 includes an inkjet head 3 (hereinafter referred to as the "head 3") that discharges ink toward a print medium 2, a carriage 4 on which the head 3 is mounted, and a carriage 4 that moves in the main scanning direction (see FIG. A carriage drive mechanism 5 for moving the carriage 4 in the Y direction), a guide rail 6 for guiding the carriage 4 in the main scanning direction, and a plurality of ink tanks 7 containing ink to be supplied to the head 3. . In the following explanation, the main scanning direction (Y direction) is referred to as the "left-right direction", and the vertical direction (Z direction in Figure 1, etc.) and the sub-scanning direction (X direction in Figure 1, etc.) perpendicular to the main scanning direction is referred to as " "Anteroposterior direction". Further, one side in the front-back direction, the X1 direction side in FIG. 1, etc., is defined as the "front" side, and the other side in the front-back direction, the X2 direction side in FIG. 1, etc., is defined as the "rear" side.

The printer 1 also includes a pressure adjustment mechanism 11 for adjusting the internal pressure of the head 3, an ink warming mechanism 12 for warming the ink supplied to the head 3, and a temperature detection system for detecting the temperature of the ink inside the head 3. The printer 1 includes an internal head temperature sensor 13 for detecting the temperature outside the printer 1, and an external temperature sensor 14 for detecting the temperature outside the printer 1 (external temperature). Further, the printer 1 includes a control section 9 that controls the printer 1. A host device 10 of the printer 1 such as a PC (personal computer) is electrically connected to the control section 9 .

A plurality of nozzles 3a are formed on the lower surface of the head 3 to eject ink. The plurality of nozzles 3a are arranged at a constant pitch in the front-rear direction, and the plurality of nozzles 3a arranged in the front-rear direction constitute a nozzle row 3b. In this embodiment, a plurality of nozzle rows 3b are formed on the lower surface of the head 3. The plurality of nozzle rows 3b are arranged in the left-right direction. Inside the head 3, a plurality of ink channels 3c to 3f are formed, each of which connects a plurality of nozzle rows 3b. That is, the head 3 is formed with a plurality of ink channels 3c to 3f to which a plurality of nozzles 3a are connected. One end of each of the ink channels 3c to 3f serves as an ink inlet 3g through which ink flows toward the head 3. The ink inlet 3g is formed on the front end side of the head 3.

In this embodiment, for example, four nozzle rows 3b are formed on the lower surface of the head 3, and four ink flow paths 3c to 3f connected to each of the four nozzle rows 3b are formed in the head 3. . The ink channels 3c to 3f are arranged in this order from one end of the head 3 in the left-right direction toward the other end. For example, inks of different colors flow in each of the four ink channels 3c to 3f. However, ink of the same color may flow in at least two of the four ink channels 3c to 3f.

A platen 8 is arranged below the head 3. The print medium 2 for printing is placed on the platen 8 . The print medium 2 placed on the platen 8 is conveyed in the front-rear direction by a medium feeding mechanism (not shown). The carriage drive mechanism 5 includes, for example, two pulleys, a belt that spans the two pulleys and is partially fixed to the carriage 4, and a motor that rotates the pulleys. Note that the carriage 4 is equipped with an ultraviolet irradiator (not shown) that irradiates the ink ejected from the head 3 with ultraviolet rays to cure the ink.

The head 3 includes a plurality of piezoelectric elements 16 that eject ink from each of the plurality of nozzles 3a. The head 3 also includes a driver IC (Integrated Circuit) 17 that applies a drive voltage to the piezoelectric element 16 to drive the piezoelectric element 16, and an in-head heater 18 that heats the ink inside the head 3. . The piezoelectric element 16, driver IC 17, and in-head heater 18 are arranged inside the head 3. The piezoelectric element 16 is electrically connected to the control section 9. The piezoelectric element 16 of this embodiment is an ejection energy generating element. Note that the driver IC 17 does not need to be placed inside the head 3. In this case, for example, the driver IC 17 is mounted on a circuit board mounted on the carriage 4.

The head internal temperature sensor 13 is arranged inside the head 3 . In this embodiment, one in-head temperature sensor 13 is arranged inside the head 3. For example, as shown in FIG. 5, the head internal temperature sensor 13 is arranged above the rear ends of the ink channels 3c to 3f. Further, the head internal temperature sensor 13 is arranged outside the ink channels 3c to 3f. The head internal temperature sensor 13 indirectly detects the temperature of the ink inside the head 3 (specifically, the ink in the ink channels 3c to 3f) by detecting the temperature of the main body frame of the head 3. do. The head internal temperature sensor 13 is electrically connected to the control section 9 . Note that the head internal temperature sensor 13 may be placed in any one of the ink channels 3c to 3f.

The in-head heater 18 heats the ink inside the head 3 (specifically, the ink inside the ink flow paths 3c to 3f) by heating the main body frame of the head 3, thereby increasing the temperature of the ink inside the head 3. It functions to reduce viscosity. The in-head heater 18 is arranged above the ink channels 3c to 3f. Further, the in-head heater 18 is arranged at the center inside the head 3. In this embodiment, the ink in the ink channels 3d and 3e is more easily heated by the heat from the in-head heater 18 than the ink in the ink channels 3c and 3f. That is, the heating temperature of the ink in the ink channels 3c to 3f heated by the in-head heater 18 varies depending on the ink channels 3c to 3f.

The in-head heater 18 is electrically connected to the control section 9 . The control unit 9 controls the in-head heater 18 based on the detection result of the in-head temperature sensor 13 . Specifically, when the temperature detected by the head internal temperature sensor 13 is lower than a predetermined set temperature, the control unit 9 drives the head internal heater 18 so that the temperature detected by the head internal temperature sensor 13 is lower than a predetermined set temperature. When the temperature exceeds the set temperature, the in-head heater 18 is stopped. Note that the in-head heater 18 includes a temperature sensor (not shown) for detecting an overheating state of the in-head heater 18. This temperature sensor is, for example, a thermistor, and is attached to the in-head heater 18.

Ink is supplied to the pressure adjustment mechanism 11 from the ink tank 7. Specifically, the ink tank 7 is arranged above the pressure adjustment mechanism 11, and ink is supplied from the ink tank 7 to the pressure adjustment mechanism 11 due to the water head difference. The ink warming mechanism 12 is disposed between the pressure adjustment mechanism 11 and the head 3 on the ink supply path to the head 3 . Ink is supplied to the ink warming mechanism 12 from the pressure adjustment mechanism 11 , and ink is supplied to the head 3 from the ink warming mechanism 12 . The pressure adjustment mechanism 11 and the ink warming mechanism 12 are mounted on the carriage 4.

The ink warming mechanism 12 is an extra-head ink warming device disposed outside the head 3 . The ink warming mechanism 12 functions to reduce the viscosity of the ink supplied to the head 3 by warming the ink supplied to the head 3. The ink warming mechanism 12 is arranged above the head 3. The ink heating mechanism 12 includes a heating unit main body 20 formed in a block shape, an external head heater 21 attached to the heating unit main body 20, and an external head temperature sensor 22 attached to the heating unit main body 20. ing.

The heating unit main body 20 is formed into a substantially rectangular parallelepiped shape as a whole. Further, the heating section main body 20 is made of a metal material with high thermal conductivity, such as an aluminum alloy. A plurality of heating mechanism ink channels 20c to 20f through which ink flows are formed inside the heating unit main body 20. In this embodiment, four heating mechanism ink channels 20c to 20f are formed in the heating unit main body 20, each of which connects to each of the four ink channels 3c to 3f of the head 3. For example, the heating mechanism ink flow path 20c is connected to the ink flow path 3c, the heating mechanism ink flow path 20d is connected to the ink flow path 3d, the heating mechanism ink flow path 20e is connected to the ink flow path 3e, The heating mechanism ink flow path 20f is connected to the ink flow path 3f.

Of the four heating mechanism ink channels 20c to 20f, the length (flow path length) of at least one of the warming mechanism ink channels 20c to 20f is the same as that of the other heating mechanism ink channels 20c to 20f. The flow path length is different. For example, the passage length of the heating mechanism ink passage 20c and the passage length of the heating mechanism ink passage 20f are equal, and the passage length of the heating mechanism ink passage 20d is equal to the passage length of the heating mechanism ink passage 20e. The flow path lengths of the heating mechanism ink flow paths 20c and 20f are the same, and the flow path lengths of the heating mechanism ink flow paths 20d and 20e are different. Alternatively, the lengths of the four heating mechanism ink channels 20c to 20f are different from each other.

Also, the cross-sectional area of at least one of the four heating mechanism ink channels 20c to 20f (the cross section of the cross section perpendicular to the longitudinal direction of the ink channels 20c to 20f) The average value of the cross-sectional areas of the other heating mechanism ink channels 20c to 20f is different from the average value of the cross-sectional areas of the other heating mechanism ink channels 20c to 20f. For example, the average cross-sectional area of the heating mechanism ink flow path 20c is equal to the average cross-sectional area of the heating mechanism ink flow path 20f, and the average cross-sectional area of the heating mechanism ink flow path 20d is equal to the average cross-sectional area of the heating mechanism ink flow path 20f. The average value of the cross-sectional area of the heating mechanism ink flow path 20e is equal to the average value of the cross-sectional area of the heating mechanism ink flow path 20c, 20f, and the average value of the cross-sectional area of the heating mechanism ink flow path 20d, 20e. The value is different. Alternatively, the average values of the cross-sectional areas of the four heating mechanism ink channels 20c to 20f are different from each other.

The outside head heater 21 heats the heating section main body 20 . The outside head heater 21 is a sheet heater formed in a sheet shape. The outside head heater 21 is attached to the side surface of the heating section main body 20. In this embodiment, one off-head heater 21 is bent at 90 degrees at two locations and is attached to both left and right side surfaces and the front surface of the heating section main body 20. The outside head heater 21 and the outside head temperature sensor 22 are electrically connected to the control section 9 . The control unit 9 controls the outside head heater 21 based on the detection result of the outside head temperature sensor 22 .

The distance between at least one heating mechanism ink flow path 20c to 20f of the four heating mechanism ink flow paths 20c to 20f and the outside head heater 21 is the same as that of the other heating mechanism ink flow paths 20c to 20f. and the distance from the outside head heater 21. For example, the distance between the heating mechanism ink flow path 20c and the outside head heater 21 is equal to the distance between the heating mechanism ink flow path 20f and the outside head heater 21, and the distance between the heating mechanism ink flow path 20d and the outside head heater 21 is equal. The distance to the heater 21 is equal to the distance between the heating mechanism ink flow path 20e and the outside head heater 21, and the distance between the heating mechanism ink flow path 20c, 20f and the outside head heater 21 is equal to the distance between the heating mechanism ink flow path 20e and the outside head heater 21. The distances between the heating mechanism ink channels 20d and 20e and the outside head heater 21 are different.

The pressure adjustment mechanism 11 is attached to the ink warming mechanism 12. In this embodiment, two pressure adjustment mechanisms 11 are attached to one ink warming mechanism 12. A lower portion of the pressure adjustment mechanism 11 is housed in the heating section main body 20. The pressure adjustment mechanism 11 is, for example, a mechanical pressure damper configured similarly to the pressure adjustment damper described in JP-A No. 2011-46070, and does not require a pump for pressure adjustment. Adjust the pressure mechanically. Further, the pressure adjustment mechanism 11 adjusts the internal pressure of the head 3 (internal pressure of the ink flow path 3c) to negative pressure. Two ink flow paths (not shown) are formed inside the pressure adjustment mechanism 11.

The external temperature sensor 14 is mounted on the carriage 4, for example. Alternatively, the external temperature sensor 14 is attached to the operation panel of the printer 1 or to the main body frame. External temperature sensor 14 is electrically connected to control section 9 .

(Inkjet printer control method)
FIG. 8 is a diagram for explaining an example of the measurement results of the ink temperatures in each of the ink flow paths 3c to 3f, which are stored in the control unit 9 shown in FIG. FIG. 9 is a diagram for explaining an example of a table stored in the control unit 9 shown in FIG. 4.

In this embodiment, if the amount of ink ejected from the plurality of nozzles 3a connected to each of the four ink channels 3c to 3f varies depending on the ink channels 3c to 3f (that is, the amount of ink consumed is 3f), the flow rate of ink flowing into each of the four ink channels 3c to 3f varies, so the time required for the ink to pass through each of the heating mechanism ink channels 20c to 20f is The temperature of the ink flowing into each of the four ink channels 3c to 3f varies depending on the ink channels 20c to 20f, and as a result, the temperature of the ink in each of the four ink channels 3c to 3f may vary. be.

Furthermore, even if the flow rate of ink flowing into each of the four ink flow paths 3c to 3f does not vary, the heating mechanism can maintain the average value of the length and cross-sectional area of each of the ink flow paths 20c to 20f. Due to variations in the mechanism ink flow paths 20c to 20f and variations in the distance between each of the heating mechanism ink flow paths 20c to 20f and the outside head heater 21 due to the heating mechanism ink flow paths 20c to 20f, the ink heating mechanism As a result, the temperature of the ink heated by the heating mechanism 12 varies depending on the heating mechanism ink channels 20c to 20f, and the temperature of the ink flowing into each of the four ink channels 3c to 3f varies. The temperature of the ink in each of the 3f may vary.

Furthermore, even if the temperature of the ink flowing into each of the four ink channels 3c to 3f does not vary, the ink flow has a heating temperature of the ink in the ink channels 3c to 3f heated by the in-head heater 18. Due to variations in the paths 3c to 3f, the temperature of the ink in each of the four ink flow paths 3c to 3f may vary.

According to the inventor's study, there are cases where the external temperature of the printer 1 is low and the ink cannot be sufficiently heated by the ink heating mechanism 12, or when the flow rate of ink flowing into the ink channels 3c to 3f is large (i.e. In each of the four ink flow paths 3c to 3f, when the ink cannot be sufficiently heated by the ink heating mechanism 12 (because the passage time of the ink passing through the ink flow paths 20c to 20f is short), Dispersion in ink temperature is likely to occur. Further, when the temperature of the ink in each of the four ink channels 3c to 3f varies, the viscosity of the ink in each of the four ink channels 3c to 3f varies.

Therefore, in this embodiment, even if the viscosity of the ink in each of the four ink channels 3c to 3f varies, the variation in the amount and velocity of ink ejected from the plurality of nozzles 3a among the ink channels 3c to 3f is reduced. When the printer 1 prints on the print medium 2, the control unit 9 controls the flow rate of ink flowing into each of the four ink flow paths 3c to 3f (that is, the flow rate from the ink heating mechanism 12) so that Based on the ink flow rate, which is the flow rate per unit time of the ink flowing into each of the four ink channels 3c to 3f, and the external temperature of the printer 1 detected by the external temperature sensor 14, The temperature of the ink in each of the flow paths 3c to 3f is estimated, and the drive voltages applied to the plurality of piezoelectric elements 16 are controlled based on the estimation results. Specifically, the control unit 9 controls the drive voltages applied to the plurality of piezoelectric elements 16 as follows.

In this embodiment, the external temperature detected by the external temperature sensor 14 is the first temperature, which is the temperature outside the head 3, and the control unit 9 sets the external temperature detected by the external temperature sensor 14 to the first temperature. 1 temperature. In addition, in the following description, a piezoelectric element 16 that ejects ink from a plurality of nozzles 3a connected to an ink flow path 3c, a piezoelectric element 16 that ejects ink from a plurality of nozzles 3a connected to an ink flow path 3d, and an ink flow path When the piezoelectric element 16 that causes ink to be ejected from the plurality of nozzles 3a connected to the ink flow path 3e is distinguished from the piezoelectric element 16 that causes ink to be ejected from the plurality of nozzles 3a that are connected to the ink flow path 3f, the piezoelectric element 16 that causes ink to be ejected from the plurality of nozzles 3a that are connected to the ink flow path 3f are to be distinguished from each other. Each of the plural piezoelectric elements 16 that ejects ink from the plurality of nozzles 3a is referred to as a "piezoelectric element 16C", and each of the plurality of piezoelectric elements 16 that ejects ink from the plurality of nozzles 3a connected to the ink flow path 3d is referred to as a "piezoelectric element 16C". 16D", and each of the plurality of piezoelectric elements 16 that ejects ink from the plurality of nozzles 3a connected to the ink flow path 3e is referred to as "piezoelectric element 16E", and each of the plurality of piezoelectric elements 16 that ejects ink from the plurality of nozzles 3a connected to the ink flow path 3f. Each of the piezoelectric elements 16 is referred to as a "piezoelectric element 16F".

Further, in this embodiment, the control unit 9 can individually control the piezoelectric element 16C, the piezoelectric element 16D, the piezoelectric element 16E, and the piezoelectric element 16F. On the other hand, the control unit 9 cannot individually control each of the plurality of piezoelectric elements 16C. That is, the same drive voltage is applied to the plurality of piezoelectric elements 16C. Similarly, the same drive voltage is applied to the plurality of piezoelectric elements 16D, the same drive voltage is applied to the plurality of piezoelectric elements 16E, and the same drive voltage is applied to the plurality of piezoelectric elements 16F. That is, the control unit 9 applies the same drive voltage to the plurality of piezoelectric elements 16 that cause ink to be ejected from the nozzles 3a connected to the same ink channels 3c to 3f.

Before printing the print medium 2, the ink temperature in each of the four ink flow paths 3c to 3f is measured in advance according to various ink flow rates and external temperatures of the printer 1, and this measurement result is used for control. It is stored in advance in section 9. Specifically, four ink flow paths are formed according to the target heating temperature of the ink heated by the in-head heater 18 (target value of the ink heating temperature), various ink flow rates, and external temperatures. The temperature of the ink at each of 3c to 3f is measured in advance, and the measurement results are stored in the control section 9 in advance. In this embodiment, the optimum temperature of the ink ejected from the head 3 is 45°C, and the target heating temperature is 45°C.

For example, as shown in FIG. 8, when the external temperature is T1 and the ink flow rates in the ink channels 3c to 3f are Q1, Q2, Q3, etc., the ink temperatures in the ink channel 3c are T11, T12, T13, etc. ..., the temperature of the ink in the ink flow path 3d T21, T22, T23..., the temperature of the ink in the ink flow path 3e T31, T32, T33..., and the temperature of the ink in the ink flow path 3f T41, T42 , T43... are measured in advance before printing the print medium 2. Similarly, when the external temperature is T2 and the ink flow rates of the ink channels 3c to 3f are Q1, Q2, Q3..., the ink temperature in each of the four ink channels 3c to 3f and the external temperature The temperature of the ink in each of the four ink flow paths 3c to 3f when the ink flow rate is T3 and the ink flow rate is Q1, Q2, Q3, . Further, these measurement results are stored in a table in advance in the control unit 9.

Note that when measuring the ink temperature in each of the four ink channels 3c to 3f according to various ink flow rates and external temperatures, for example, at least one ink flow path is measured at the same ink flow rate and external temperature. The inside of the head is heated so that the temperature of the ink in 3c to 3f reaches the target heating temperature of 45°C, and the temperature of the ink in all four ink flow paths 3c to 3f is 45°C or less. The heater 18 and the outside head heater 21 are controlled.

For example, when the external temperature is T1 and the ink flow rate in the ink flow paths 3c to 3f is Q1, the ink temperature in the ink flow path 3c is T11, the ink temperature in the ink flow path 3d is T21, and the ink flow rate in the ink flow path 3e is 4 in such a way that at least one of the ink temperature T31 of the ink flow path 3f and the ink temperature T41 of the ink flow path 3f is 45°C, and all of T11, T21, T31, and T41 are 45°C or less. When measuring the temperature of ink in each of the ink flow paths 3c to 3f, the in-head heater 18 and the out-of-head heater 21 are controlled.

When printing the print medium 2, first, print data for printing on the print medium 2 is input from the host device 10 to the control unit 9. The control unit 9 specifies the ink flow rate in each of the four ink flow paths 3c to 3f based on the print data input to the control unit 9. For example, the control unit 9 calculates the ink flow rate in each of the four ink flow paths 3c to 3f by performing a predetermined calculation based on the print data input to the control unit 9.

The control unit 9 also controls the four ink flow paths 3c based on the specified ink flow rate, the external temperature of the printer 1 detected by the external temperature sensor 14, and the measurement results stored in the control unit 9. Estimate the temperature of the ink at each of 3f to 3f. That is, the control unit 9 refers to a table (the table shown in FIG. 8) stored in the control unit 9 based on the specified ink flow rate and the external temperature detected by the external temperature sensor 14, and The temperature of ink in each of the ink channels 3c to 3f of the book is estimated.

Further, the control unit 9 stores a table (see FIG. 9) in which the drive voltage of the piezoelectric element 16 and the temperature of the ink are associated in advance, and the control unit 9 uses this table based on the estimation results. The driving voltages applied to the plurality of piezoelectric elements 16 are controlled with reference to . In addition, in the table shown in FIG. 9, the drive voltage of the piezoelectric element 16 is set according to each ink temperature so that the amount and speed of ink ejection from the nozzle 3a are constant regardless of the ink temperature. has been done.

For example, the external temperature detected by the external temperature sensor 14 is T1, the ink flow rate in the specified ink flow path 3c is Q1, the ink flow rate in the specified ink flow path 3d is Q2, and the specified ink flow path When the ink flow rate of the ink flow path 3e is Q3 and the ink flow rate of the specified ink flow path 3f is Q1, the control unit 9 estimates the temperature of the ink of the ink flow path 3c to be T11, and the temperature of the ink flow of the ink flow path 3d is estimated to be T11. The temperature of the ink is estimated to be T22, the temperature of the ink in the ink flow path 3e is estimated to be T33, and the temperature of the ink in the ink flow path 3f is estimated to be T41.

Further, for example, if T11 is 42°C, T22 is 44°C, T33 is 45°C, and T41 is estimated to be 43°C, the control unit 9 controls the drive voltage associated with 42°C. V1+0.828 (V) is applied to the piezoelectric element 16C, a driving voltage V1+0.276 (V) corresponding to 44°C is applied to the piezoelectric element 16D, and a driving voltage V1 (V) corresponding to 45°C is applied to the piezoelectric element 16C. A drive voltage V1+0.552 (V) corresponding to 43° C. is applied to the piezoelectric element 16F.

The control unit 9 estimates the ink temperature in each of the four ink flow paths 3c to 3f based on the ink flow rate and external temperature every time printing is performed on one print medium 2, and calculates the temperature of the ink in each of the four ink channels 3c to 3f. Based on the results, the drive voltages applied to the plurality of piezoelectric elements 16 are updated and set. Alternatively, each time the carriage 4 performs one scanning operation in the main scanning direction during printing on the print medium 2, the control unit 9 controls the four ink flow paths 3c to 3f based on the ink flow rate and external temperature. The ink temperature at each of the piezoelectric elements 16 is estimated, and the drive voltages applied to the plurality of piezoelectric elements 16 are updated and set based on the estimation results.

Alternatively, the control unit 9 estimates the ink temperature in each of the four ink flow paths 3c to 3f in real time based on the ink flow rate and the external temperature, and based on this estimation result, the plurality of piezoelectric elements The drive voltage applied to 16 is updated and set. That is, the control unit 9 controls the four ink flow paths 3c to 3f based on the ink flow rate and external temperature even while the carriage 4 is performing a scanning operation in the main scanning direction during printing on the print medium 2. The temperature of the ink in each is estimated, and the drive voltages applied to the plurality of piezoelectric elements 16 are updated and set based on the estimation results.

(Main effects of this form)
As described above, in this embodiment, the control unit 9 controls the four ink channels 3c to 3f based on the ink flow rate flowing into each of the four ink channels 3c to 3f and the external temperature of the printer 1. In addition to estimating the temperature of the ink at each of the points 3f to 3f, the drive voltages applied to the plurality of piezoelectric elements 16 are controlled based on the estimation results. Therefore, in this embodiment, the temperature of the ink in the four ink channels 3c to 3f varies depending on the temperature of the ink in the four ink channels 3c to 3f due to variations in the flow rate of ink flowing into each of the four ink channels 3c to 3f. As a result, even if the viscosity of the ink ejected from the plurality of nozzles 3a varies among the ink channels 3c to 3f, the temperature of the ink in each of the four ink channels 3c to 3f is estimated. It becomes possible to control the drive voltage applied to the plurality of piezoelectric elements 16 so that variations in the amount and speed of ink ejected from the plurality of nozzles 3a due to the ink flow paths 3c to 3f are suppressed. . Therefore, in this embodiment, it is possible to suppress deterioration in print quality regardless of printing conditions.

In particular, in this embodiment, variations in the average lengths and cross-sectional areas of the heating mechanism ink channels 20c to 20f, and variations in the average values of the lengths and cross-sectional areas of the heating mechanism ink channels 20c to 20f, and Variations in the distance between the heater 21 and the heater 21 outside the head due to the heating mechanism ink flow paths 20c to 20f, and the degree of heating of ink in the ink flow paths 3c to 3f heated by the ink head heater 18 in the ink flow path 3c. 3f, the temperature of the ink in the four ink channels 3c to 3f tends to vary depending on the ink channels 3c to 3f, but in this embodiment, the ink in the four ink channels 3c to 3f A plurality of piezoelectric elements are used to suppress variations in the amount and speed of ink ejection from the plurality of nozzles 3a due to the ink flow paths 3c to 3f, even if the temperature of the ink flow paths 3c to 3f tends to vary. It becomes possible to control the drive voltage applied to 16.

In this embodiment, the control unit 9 specifies the ink flow rate in each of the four ink flow paths 3c to 3f based on the print data input to the control unit 9. Therefore, in this embodiment, it is possible to simplify the mechanical configuration of the printer 1 and relatively easily determine the ink flow rate in each of the four ink flow paths 3c to 3f.

In this embodiment, the temperature of ink in each of the four ink flow paths 3c to 3f is measured in advance according to various ink flow rates and external temperatures of the printer 1, and the measurement results are stored in the control unit 9 in advance. has been done. In addition, in this embodiment, the control unit 9 controls the four The temperature of ink in each of the ink channels 3c to 3f is estimated. Therefore, in this embodiment, it is possible to simplify the processing of the control unit 9 when estimating the temperature of ink in each of the four ink flow paths 3c to 3f.

(Modified example of inkjet printer control method)
In the embodiment described above, the printer 1 may include a plurality of in-head temperature sensors 13 for detecting the temperature of ink in each of the four ink flow paths 3c to 3f. For example, the printer 1 may include four in-head temperature sensors 13 arranged near each of the four ink flow paths 3c to 3f, as shown by the two-dot chain line in FIG. In this case, the head internal temperature sensor 13 is arranged, for example, above each of the rear end portions of the ink flow paths 3c to 3f. The head internal temperature sensor 13 in this modification is an ink temperature sensor.

In this modification, the control unit 9 controls the drive voltages applied to the plurality of piezoelectric elements 16 based on the detection results of the four head internal temperature sensors 13. For example, the temperature of the ink flow path 3c detected by the head internal temperature sensor 13 located above the ink flow path 3c is 42°C, and the temperature detected by the head internal temperature sensor 13 located above the ink flow path 3d. The temperature of the ink flow path 3d is 44°C, the temperature of the ink flow path 3e detected by the head internal temperature sensor 13 disposed above the ink flow path 3e is 45°C, and the temperature of the ink flow path 3f is 45°C. When the temperature of the ink flow path 3f detected by the head internal temperature sensor 13 disposed on the upper side is 43° C., the control unit 9 applies the drive voltage V1 + 0.828 (V) to the piezoelectric element 16C, A drive voltage V1+0.276 (V) is applied to the piezoelectric element 16D, a drive voltage V1 (V) is applied to the piezoelectric element 16E, and a drive voltage V1+0.552 (V) is applied to the piezoelectric element 16F. Note that in this modification, the control unit 9 does not need to specify the ink flow rate of each of the four ink flow paths 3c to 3f. Furthermore, in this modification, there is no need to measure ink temperatures in each of the four ink flow paths 3c to 3f in advance in accordance with various ink flow rates and external temperatures.

In this modification, as in the above-described embodiment, the temperature of the ink in the four ink channels 3c to 3f may vary due to variations in the flow rate of ink flowing into each of the four ink channels 3c to 3f. Even if the viscosity of the ink ejected from the plurality of nozzles 3a varies depending on the ink channels 3c to 3f, based on the detection results of the four head internal temperature sensors 13, It becomes possible to control the drive voltage applied to the plurality of piezoelectric elements 16 so that variations in the amount and speed of ink ejected from the plurality of nozzles 3a due to the ink channels 3c to 3f are suppressed. Therefore, in this modification as well, it is possible to suppress deterioration in print quality regardless of the conditions at the time of printing. Furthermore, in this modification, since the head internal temperature sensor 13 is disposed near each of the four ink channels 3c to 3f, the head internal temperature sensor 13 detects the temperature of the four ink channels 3c to 3f. It becomes possible to accurately detect the temperature of the ink at each point.

Note that in this modification, the head internal temperature sensor 13 may be arranged in each of the four ink flow paths 3c to 3f. Even in this case, the in-head temperature sensor 13 can accurately detect the temperature of the ink in each of the four ink flow paths 3c to 3f. In addition, in this modification, if the temperature of the ink in each of the four ink channels 3c to 3f can be appropriately detected, the temperature of the ink in each of the four ink channels 3c to 3f can be detected appropriately. The four ink temperature sensors for detection may be placed outside the head 3. For example, an ink temperature sensor may be placed near the ink outlet of each of the heating mechanism ink channels 20c to 20f.

Further, as in this modification, when the head internal temperature sensor 13 is arranged near each of the four ink flow paths 3c to 3f, the four ink flow paths 3c to 3f are formed. By arranging one in-head heater 18 at each position and controlling the four in-head heaters 18 individually based on the detection results of the four in-head temperature sensors 13, four ink flows can be controlled. Although it is possible to suppress variations in the temperature of the ink in each of the paths 3c to 3f, according to the inventor's study, the four in-head heaters 18 are controlled based on the detection results of the four in-head temperature sensors 13 Even if each of the four ink channels 3c to 3f is controlled individually, the temperature of the ink in the ink channels 3c to 3f does not change immediately with the temperature fluctuation of the in-head heater 18. It is difficult to suppress variations in ink temperature.

(Other embodiments)
Although the above-described embodiments and modifications are examples of preferred embodiments of the present invention, the present invention is not limited thereto, and various modifications can be made without changing the gist of the present invention.

In the embodiment described above, the printer 1 may include four flowmeters for detecting the flow rate of ink flowing into each of the four ink flow paths 3c to 3f. In this case, a flowmeter is installed in each of the four ink flow paths 3c to 3f, and the control unit 9 controls the four ink flow paths 3c to 3f based on the detection results of the four flowmeters. Specify the ink flow rate flowing into each of 3f. Further, in the above-described embodiment, the ink warming mechanism 12 may include four flowmeters for detecting the flow rate of ink in each of the warming mechanism ink channels 20c to 20f. In this case, a flowmeter is installed in each of the four ink flow paths 20c to 20f, and the control unit 9 controls the four ink flow paths 3c to 3c based on the detection results of the four flowmeters. Specify the ink flow rate flowing into each of 3f.

In the above-described embodiment, when the printer 1 prints the print medium 2, the control unit 9 controls the ink flow rate of each of the four ink channels 3c to 3f and the head 3 detected by the head external temperature sensor 22. The temperature of the ink in each of the four ink flow paths 3c to 3f may be estimated based on the first temperature which is the external temperature of the ink flow path. In this case, before printing on the print medium 2, the target heating temperature of the ink heated by the in-head heater 18 and various ink flow rates and first temperatures (specifically, The temperature of the ink in each of the four ink flow paths 3c to 3f is measured in advance according to the detected first temperature), and the measurement results are stored in the control section 9 in advance.

Further, in the above-described embodiment, when the printer 1 prints on the print medium 2, the control unit 9 controls the ink flow rate of each of the four ink channels 3c to 3f and the temperature inside the head 3. The temperature of the ink in each of the four ink flow paths 3c to 3f may be estimated based on the 1 temperature. For example, the control unit 9 controls each of the four ink channels 3c to 3f based on the ink flow rate of each of the four ink channels 3c to 3f and the first temperature detected by the head internal temperature sensor 13. The temperature of the ink at each point may be estimated. In this case, before printing on the print medium 2, the target heating temperature of the ink heated by the in-head heater 18, the various ink flow rates and the first temperature (specifically, the in-head temperature sensor 13 The temperature of the ink in each of the four ink flow paths 3c to 3f is measured in advance according to the detected first temperature), and the measurement results are stored in the control section 9 in advance.

In the above embodiments and modifications, the lengths of the four heating mechanism ink channels 20c to 20f may be equal to each other. Further, in the above-described embodiment, the average value of the cross-sectional area of each of the four heating mechanism ink channels 20c to 20f may be equal to each other. Furthermore, in the above-described embodiment, the distances between each of the four heating mechanism ink flow paths 20c to 20f and the outside-head heater 21 may be equal to each other. Further, in the above-described embodiment, the in-head heater 18 may evenly heat the ink in the ink channels 3c to 3f.

Note that the average value of the flow path length and cross-sectional area of each of the four heating mechanism ink passages 20c to 20f is equal to each other, and that each of the four heating mechanism ink passages 20c to 20f and the heater outside the head are equal to each other. Even if the distances from the four ink channels 3c to 3f are equal and the in-head heater 18 uniformly warms the ink in the ink channels 3c to 3f, the ink flowing into each of the four ink channels 3c to 3f When the flow rate varies, the temperature of the ink in each of the four ink flow paths 3c to 3f varies.

In the embodiments and modifications described above, the number of ink channels formed in the head 3 may be two or three, or five or more. Further, in the above-described embodiments and modifications, the control unit 9 may be able to individually control each of the plurality of piezoelectric elements 16. Furthermore, in the above-described embodiments and modifications, the head 3 does not need to include the in-head heater 18. Furthermore, in the embodiments and modifications described above, the printer 1 does not need to include the ink warming mechanism 12.

In the above embodiments and modifications, the ejection energy generating element for ejecting ink from the nozzle 3a is the piezoelectric element 16, but the ejection energy generating element for ejecting ink from the nozzle 3a is a heater (heating element). It may be. That is, in the embodiments and modifications described above, the printer 1 ejects ink from the nozzles 3a using a piezo method, but the printer 1 may eject ink from the nozzles 3a using a thermal method.

In the above-described embodiments and modifications, the ink used in the printer 1 may be an ink other than UV ink that has a high viscosity at room temperature and whose viscosity fluctuates greatly with temperature fluctuations. It may be an ink that does not have such characteristics. Furthermore, in the above-described embodiments and modifications, the printer 1 may include, in place of the platen 8, a table on which the print medium 2 is placed and a table drive mechanism that moves the table in the front-back direction. Furthermore, in the above-described embodiments and modifications, the printer 1 may be a 3D printer that forms a three-dimensional object.

1 Printer (inkjet printer)
3 head (inkjet head)
3a nozzle 3c to 3f ink flow path 9 control unit 12 ink heating mechanism 13 head internal temperature sensor (ink temperature sensor)
14 External temperature sensor 16 Piezoelectric element (discharge energy generating element)
18 In-head heater 20 Heating unit body 20c to 20f Heating mechanism ink flow path 21 Out-of-head heater

Claims (8)

In an inkjet printer that prints by ejecting ink,
An inkjet head in which a plurality of nozzles for ejecting ink and a plurality of ink flow paths connecting the plurality of nozzles are formed, an external temperature sensor for detecting an external temperature of the inkjet printer, and a control unit for controlling the inkjet printer. and
The inkjet head includes a plurality of ejection energy generating elements that eject ink from each of the plurality of nozzles,
The control unit controls the control of the plurality of ink channels based on an ink flow rate that is a flow rate of ink flowing into each of the plurality of ink channels and a first temperature that is an internal or external temperature of the inkjet head. The temperature of the ink at each of the ejection energy generating elements is estimated, based on the estimation result, the drive voltage applied to the plurality of ejection energy generating elements is controlled, and the temperature of the ink at each of the plurality of ejection energy generating elements is controlled based on the print data input to the control section. An inkjet printer characterized in that the ink flow rate in each of the ink flow paths is specified, and the external temperature detected by the external temperature sensor is set as the first temperature. In an inkjet printer that prints by ejecting ink,
An inkjet head in which a plurality of nozzles for ejecting ink and a plurality of ink flow paths connecting the plurality of nozzles are formed, and a control section for controlling the inkjet printer,
The inkjet head includes a plurality of ejection energy generating elements that eject ink from each of the plurality of nozzles,
The control unit controls the control of the plurality of ink channels based on an ink flow rate that is a flow rate of ink flowing into each of the plurality of ink channels and a first temperature that is an internal or external temperature of the inkjet head. estimating the temperature of the ink at each point, and controlling the drive voltage applied to the plurality of ejection energy generating elements based on the estimation results;
The temperature of the ink in each of the plurality of ink flow paths is measured in advance according to various ink flow rates and the first temperature, and the measurement results are stored in the control unit in advance,
The control unit estimates the temperature of the ink in each of the plurality of ink flow paths based on the measurement result stored in the control unit, the ink flow rate, and the first temperature. printer. The inkjet head includes an in-head heater that heats ink inside the inkjet head,
The temperature of the ink in each of the plurality of ink flow paths is measured in advance according to a target heating temperature of the ink heated by the in-head heater, various ink flow rates, and the first temperature. 3. The inkjet printer according to claim 2 , wherein the measurement results are stored in the control section in advance. In an inkjet printer that prints by ejecting ink,
An inkjet head in which a plurality of nozzles for ejecting ink and a plurality of ink flow paths connecting the plurality of nozzles are formed, an ink heating mechanism for warming ink supplied to the inkjet head, and an inkjet printer for controlling the inkjet printer. It is equipped with a control section,
The ink heating mechanism includes a block-shaped heating unit main body in which a plurality of heating mechanism ink channels through which ink flows are formed, and an external head heater that heats the heating unit main body,
Each of the plurality of heating mechanism ink channels is connected to each of the plurality of ink channels,
The inkjet head includes a plurality of ejection energy generating elements that eject ink from each of the plurality of nozzles, and an in-head heater that heats ink inside the inkjet head,
The control unit controls the plurality of ink channels based on an ink flow rate that is a flow rate of ink flowing into each of the plurality of ink channels and a first temperature that is an internal or external temperature of the inkjet head. An inkjet printer characterized in that the ink temperature in each of the inkjet printers is estimated, and the drive voltage applied to the plurality of ejection energy generating elements is controlled based on the estimation results. In an inkjet printer that prints by ejecting ink,
An inkjet head in which a plurality of nozzles for ejecting ink and a plurality of ink channels to which the plurality of nozzles are connected are formed, and a plurality of ink temperature sensors for detecting the temperature of ink in each of the plurality of ink channels. and an ink heating mechanism that warms ink supplied to the inkjet head, and a control unit that controls the inkjet printer,
The ink heating mechanism includes a block-shaped heating unit main body in which a plurality of heating mechanism ink channels through which ink flows are formed, and an external head heater that heats the heating unit main body,
Each of the plurality of heating mechanism ink channels is connected to each of the plurality of ink channels,
The inkjet head includes a plurality of ejection energy generating elements that eject ink from each of the plurality of nozzles , and an in-head heater that heats ink inside the inkjet head ,
The inkjet printer is characterized in that the control unit controls drive voltages applied to the plurality of ejection energy generating elements based on detection results of the plurality of ink temperature sensors. 6. The inkjet printer according to claim 5, wherein the ink temperature sensor is disposed near each of the plurality of ink channels or in each of the plurality of ink channels. The inkjet head includes a plurality of nozzles that eject ink and a plurality of ink channels that connect the plurality of nozzles, and the inkjet head generates a plurality of ejection energies that eject ink from each of the plurality of nozzles. A method of controlling an inkjet printer including an element,
The inkjet printer includes an external temperature sensor that detects an external temperature of the inkjet printer,
In the inkjet printer control method, the plurality of inkjet printers are controlled based on the ink flow rate, which is the flow rate of ink flowing into each of the plurality of ink channels, and the first temperature, which is the temperature inside or outside the inkjet head. The temperature of the ink in each of the ink flow paths is estimated, and the drive voltage applied to the plurality of ejection energy generating elements is controlled based on the estimation result , and the drive voltage applied to the plurality of ejection energy generating elements is controlled based on the input print data. A method for controlling an inkjet printer, characterized in that the ink flow rate in each of the ink flow paths is specified, and the external temperature detected by the external temperature sensor is set as the first temperature. An inkjet head in which a plurality of nozzles for ejecting ink and a plurality of ink channels to which the plurality of nozzles are connected are formed, and a plurality of ink temperature sensors for detecting the temperature of ink in each of the plurality of ink channels. and an ink warming mechanism that warms the ink supplied to the inkjet head , the ink warming mechanism including a block-shaped heating section in which a plurality of heating mechanism ink channels through which the ink flows are formed. and a head-external heater that heats the heating unit main body, each of the plurality of heating mechanism ink channels is connected to each of the plurality of ink channels, and the inkjet head has a plurality of ink channels. A method for controlling an inkjet printer, comprising: a plurality of ejection energy generating elements that eject ink from each of the nozzles ; and an in-head heater that heats ink inside the inkjet head .
A method for controlling an inkjet printer, comprising controlling a drive voltage applied to a plurality of ejection energy generating elements based on detection results from a plurality of ink temperature sensors.

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