JP5357817B2 - Inkjet printing device - Google Patents

Description

  The present invention relates to an inkjet printing apparatus that performs printing on printing paper by ejecting ink with an inkjet head.

  In general, an inkjet printing apparatus to which an inkjet method is applied prints images, characters, and the like by ejecting ink from a nozzle of an inkjet head toward printing paper based on print data such as image information and character information. In addition, since print data can be printed in color on printing paper using multi-color ink, it is widely used for home use and business use.

  As such an ink jet printing apparatus, there is also well known an ink circulation type that continuously circulates ink in order to remove ink impurities such as heating of ink and dust mixed in the ink.

  The ink used in this ink circulation type ink jet printing apparatus has a temperature characteristic that the viscosity changes depending on the temperature condition such that the viscosity is high at a low temperature and the viscosity is low at a high temperature. In particular, when the viscosity of the ink increases, the size of the ink droplets and the ejection speed vary, and it may be impossible to obtain a high-definition printed matter.

  For this reason, it is necessary to perform a warm-up operation for heating the ink so as to have an appropriate viscosity before printing is started. However, if the time until the completion of the warm-up operation is long, it is stressful for the user.

  Therefore, in Patent Document 1, a partition plate that rotates in the tank is provided, and the total amount of ink circulated (hereinafter referred to as total ink circulation amount) is reduced by rotating the partition plate. Ink jet printing apparatuses that shorten the time to completion have been proposed.

JP 2009-196208 A

  However, in the ink jet printing apparatus described in Patent Document 1, it is necessary to provide a partition plate that rotates in the tank, which causes a problem that the apparatus configuration is complicated.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an ink jet printing apparatus that shortens the time until the warm-up operation is completed with a simple configuration.

  In order to achieve the above object, a first feature of an ink jet printing apparatus according to the present invention is that an ink jet head that ejects ink onto a print medium and the ink between the ink jet head and an ink tank that stores the ink are disposed. The ink circulation by discharging ink with the ink jet head based on the ink circulation path to circulate, the heating means for heating the ink circulated in the ink circulation path, and the information on the viscosity of the ink. And a control means for reducing the total amount of ink circulating in the path and executing a warm-up operation for heating the ink circulated in the ink circulation path in the heating means.

  A second feature of the ink jet printing apparatus according to the present invention is that the information relating to the viscosity of the ink is history information from a point in time that is traced back a predetermined time, and the control unit is configured to control the ink jet head based on the history information. By discharging the ink, the total amount of ink circulating in the ink circulation path is reduced, and the warm-up operation is executed.

  A third feature of the ink jet printing apparatus according to the present invention is that temperature detecting means for detecting the temperature of the ink or the vicinity of the ink jet printing apparatus, and a history of temperatures detected by the temperature detecting means are stored as temperature history information. A first storage unit, wherein the control unit includes a temperature that is equal to or lower than a predetermined first threshold value in the temperature from the point in time when the temperature history information is traced back for a predetermined time. It is to reduce the total amount of ink circulating through the ink circulation path by discharging ink with the inkjet head and to execute the warm-up operation.

  A fourth feature of the ink jet printing apparatus according to the present invention is further provided with second storage means for storing the operation history of the warm-up operation as operation history information, and the control means includes a predetermined value in the operation history information. When the operation history from the time point back includes an operation history indicating that the warm-up operation has been performed for a predetermined time or more, the ink circulation is performed by ejecting ink with the inkjet head. It is to reduce the total amount of ink circulation that circulates in the path and to execute the warm-up operation.

  A fifth feature of the ink jet printing apparatus according to the present invention is further provided with third storage means for storing temperature environment information set based on an external input, and the control means is based on the temperature environment information. In other words, the total amount of ink circulating in the ink circulation path is reduced by discharging ink with the inkjet head, and the warm-up operation is executed.

  A sixth feature of the ink jet printing apparatus according to the present invention is that the control means calculates an ink amount used for printing the input print job, and the calculated ink amount is the reduced ink. When the total circulation amount is exceeded, the total ink circulation amount circulating through the ink circulation path is increased.

  According to the first feature of the ink jet printing apparatus according to the present invention, the total amount of ink circulated through the ink circulation path is reduced by causing the ink jet head to eject ink based on the information on the viscosity of the ink, and the warm-up is performed. Since the operation is executed, it is possible to shorten the time until the warm-up operation is completed with a simple configuration.

  According to the second feature of the ink jet printing apparatus according to the present invention, the information related to the viscosity of the ink is history information from a point in time that has been traced back for a predetermined time, so that the total amount of ink circulation is reduced reflecting the past history. It is possible to determine whether to reduce the total ink circulation amount more accurately.

  According to the third feature of the ink jet printing apparatus of the present invention, since the total ink circulation amount is reduced based on the temperature history information, it can be determined whether or not the total ink circulation amount is to be reduced more accurately.

  According to the fourth feature of the ink jet printing apparatus according to the present invention, since the total amount of ink circulation is reduced based on the operation history information, when the warm-up operation is performed for a relatively long time, the total amount of ink circulation is reduced. Can be reduced.

  According to the fifth aspect of the ink jet printing apparatus of the present invention, the total ink circulation amount is reduced based on the temperature environment information set based on the external input, so that the total ink circulation amount is reduced as set by the user. be able to.

  According to the sixth aspect of the ink jet printing apparatus of the present invention, since the total amount of ink circulation is reduced based on the input print job, it is possible to prevent a shortage of ink for printing the print job. it can.

FIG. 3 is a diagram schematically illustrating an ink circulation path for circulating ink ejected from nozzles of an inkjet head in the inkjet printing apparatus according to an embodiment of the present invention. It is the figure which showed the function structure of the inkjet printing apparatus which is one Embodiment of this invention. It is the flowchart which showed the process sequence of the starting process in the inkjet printing apparatus which is one Embodiment of this invention. 5 is a flowchart illustrating a predetermined procedure of a printing process in the inkjet printing apparatus according to the embodiment of the present invention. It is the flowchart which showed the process sequence of the liquid level control process in the inkjet printing apparatus which is one Embodiment of this invention. 5 is a flowchart illustrating a processing procedure of ink temperature control processing in the ink jet printing apparatus according to the embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<Configuration of inkjet printing apparatus>
In one embodiment of the present invention, an ink jet printing apparatus that prints images, characters, and the like by ejecting ink from a nozzle of an ink jet head toward printing paper based on print data such as image information and character information is taken as an example. I will explain.

  FIG. 1 is a diagram schematically illustrating an ink circulation path for circulating ink ejected from nozzles of an inkjet head in an inkjet printing apparatus 1 according to an embodiment of the present invention.

  As shown in FIG. 1, the ink jet printing apparatus 1 according to an embodiment of the present invention includes a first ink tank (hereinafter referred to as an upper ink tank) 153 in which ink IK is stored. The upper ink tank 153 and the ink supply chamber 123 provided on the upstream side in the ink jet head unit 30 that ejects ink are connected via an ink supply path 155. Is provided with a first electromagnetic valve 154.

  Further, an ink collection chamber 124 provided on the downstream side in the inkjet head unit 30, a second ink tank (hereinafter referred to as a lower ink tank) 159 for storing ink IK collected from the ink collection chamber 124, and a pump 160. The temperature controller 161 and the upper ink tank 153 are connected via an ink recovery path 156. As a result, the ink stored in the lower ink tank 159 is sent to the temperature regulator 161 side when the pump 160 is started, and the second electromagnetic valve 158 is controlled to be turned on / off, whereby the ink recovery path is set. The flow rate of ink IK flowing through 156 is controlled. The temperature controller 161 includes a heating unit including a heater for heating the ink IK and a cooling fan (both not shown) for cooling the ink IK.

  Therefore, when the ink IK is circulated in the ink circulation path 157 by the ink supply path 155 and the ink recovery path 156, the first and second electromagnetic valves 154 and 158 provided in the ink circulation path 157 are turned on, The ink IK stored in the ink tank 153 passes through the ink supply path 155 and is supplied into the ink supply chamber 123 of the inkjet head unit 30. Then, the ink IK is distributed from the ink supply chamber 123 to the plurality of inkjet heads 110 that are two-dimensionally arranged, and the ink IK is selectively ejected onto the printing paper W from each inkjet head 110.

  Further, after the ink IK is selectively ejected from the ink jet heads 110 onto the printing paper W, the surplus ink IK from the ink jet heads 110 is collected in the ink recovery chamber 124, and is discharged from the ink recovery chamber 124. The ink IK is temporarily stored in the lower ink tank 159 through the ink collection path 156.

  Thereafter, the ink IK in the lower ink tank 159 is sent out by the pump 160 and is supplied to the upper ink tank 153 via the temperature regulator 161.

  The lower ink tank 159 is connected to the ink bottle 151 filled with the ink IK. When the third electromagnetic valve 152 is turned on, the fresh ink IK stored in the ink bottle 151 becomes lower ink. It is supplied to the tank 159.

  The upper ink tank 153 includes a first upper limit liquid level detection unit 171 that detects an upper limit position of the liquid level in the upper ink tank 153 in a first liquid level mode, which will be described later, and a first upper limit liquid level detection unit 171. A second upper limit liquid level detection unit 172 that is provided in the lower portion and detects the upper limit position of the liquid level in the upper ink tank 153 in the second liquid level mode described later, and detects the lower limit of the liquid level in the upper ink tank 153. And a lower limit liquid level detection unit 173.

  The lower ink tank 159 includes a first upper limit liquid level detection unit 174 that detects an upper limit position of the liquid level in the lower ink tank 159 in a first liquid level mode, which will be described later, and a first upper limit liquid level detection unit 174. A second upper limit liquid level detection unit 175 that is provided in the lower portion and detects an upper limit position of the liquid level in the lower ink tank 159 in a second liquid level mode described later, and detects a lower limit of the liquid level in the lower ink tank 159. And a lower limit liquid level detection unit 176.

<Functional Configuration of Inkjet Printing Apparatus 1>
Next, the functional configuration of the inkjet printing apparatus 1 according to an embodiment of the present invention will be described.

  FIG. 2 is a diagram illustrating a functional configuration of the inkjet printing apparatus 1 according to the embodiment of the present invention.

  As shown in FIG. 2, the inkjet printing apparatus 1 includes a hard disk 72, a RAM 73, a third electromagnetic valve 152, a pump 160, a temperature regulator 161, a power supply unit 50, an operation unit 60, and a control unit. 70, a control unit 80, a first thermometer 91, and a second thermometer 92. Among these configurations, the configuration of the third electromagnetic valve 152, the pump 160, and the temperature regulator 161 has been described above, and thus the description thereof is omitted.

  The hard disk 72 stores various control programs executed by the control unit 70. In addition, the hard disk 72 stores the operation history of the warm-up operation, which is an operation for heating the ink IK, as warm-up operation history information, and stores the operation history of the printing process as print operation history information. Further, the hard disk 72 stores a currently set liquid level mode (first liquid level mode or second liquid level mode) and temperature environment information described later.

  The RAM 73 is composed of a nonvolatile semiconductor or the like, and stores various control programs executed by the control unit 70 and various data.

  The power supply unit 50 supplies predetermined power to the control unit 70 when the main power supply is set to ON.

  The operation unit 60 is provided on the upper part of the inkjet printing apparatus 1, and includes a display / input panel 61, a power key for setting the main power on, a start key for starting reading and printing, reading and printing, and the like. And a variety of operation keys such as a numeric keypad (not shown) for inputting the number of prints and the like, and supplies an operation signal based on a user operation to the control unit 70.

  The display / input panel 61 of the operation unit 60 includes a pressure-sensitive or electrostatic transparent touch panel disposed on the front surface and a liquid crystal display panel (none of which is shown) disposed on the back surface of the touch panel. ing. The user controls the liquid level in the second liquid level mode, for example, from November 1st to March 31st, by directly touching the surface of the touch panel with a finger while looking at the display screen of the liquid crystal display panel. Various setting input operations such as setting of temperature environment information indicating a period for performing the operation can be performed.

  The control unit 70 performs central control of the inkjet printing apparatus 1. Moreover, the control part 70 is provided with the mode setting part 70a, the temperature control part 70b, and the liquid level control part 70c on the function.

  The mode setting unit 70a sets the liquid level mode to one of the first liquid level mode and the second liquid level mode based on the information related to the viscosity of the ink.

  Here, the first liquid level mode is a mode in which the liquid levels of the upper ink tank 153 and the lower ink tank 159 are controlled to the first liquid level. Specifically, the liquid level of the upper ink tank 153 is changed to the first liquid level mode. The liquid level is controlled using the first upper limit liquid level detection unit 171 and the lower limit liquid level detection unit 173, and the liquid level in the lower ink tank 159 is changed to the first upper limit liquid level detection unit 174 and the lower limit liquid level detection unit 176. This is a mode in which the liquid level is controlled using.

  The second liquid level mode is a mode in which the liquid levels in the upper ink tank 153 and the lower ink tank 159 are controlled to a second liquid level that is lower than the first liquid level. The liquid level in the upper ink tank 153 is controlled using the second upper limit liquid level detection unit 172 and the lower limit liquid level detection unit 173, and the liquid level in the lower ink tank 159 is detected as the second upper limit liquid level. This is a mode in which the liquid level is controlled using the unit 175 and the lower limit liquid level detection unit 176.

  Further, the information related to the viscosity of the ink includes temperature history information, warm-up operation history information, printing operation history information, temperature environment information, and ink usage amount used by the print job, which will be described later.

  Here, the temperature history information includes the ink temperature T1 detected by the first thermometer 91, the environmental temperature T2 around the inkjet printing apparatus 1 detected by the second thermometer 92, and the respective detection times. Associated information. The temperature history information can be said to be one of the information on the viscosity of the ink because the viscosity of the ink decreases as the temperature of the ink increases, and the viscosity of the ink is determined when the temperature of the ink is determined.

  The warm-up operation history information is the start date / time and end date / time when the warm-up operation for heating the ink circulated in the ink circulation path to the heating unit of the temperature controller 161 is executed. When the warm-up operation for a long period of time is performed relatively recently, the viscosity of the ink can be expected to be high. Therefore, the warm-up operation history information can be said to be one of the information on the viscosity of the ink.

  The printing operation history information is information on a history of executing the printing process, and includes time information when the printing process was last executed. Since it can be expected that the warm-up operation will take a long time if the viscosity of the ink has increased since the last printing process, the printing operation history information is one of the information on the viscosity of the ink. I can say that.

  The temperature environment information is information indicating a period during which the liquid level control is performed in the second liquid level mode set based on the user's operation, and indicates a period during which the ink viscosity is expected to be high. The information can be said to be one of information related to the viscosity of the ink.

  The amount of ink used by the print job is an amount calculated so that the viscosity of the amount of ink necessary to execute the print job is not less than the printable viscosity, and is used by the print job. The amount of ink used can be said to be one piece of information related to the viscosity of the ink.

  The temperature control unit 70b controls the temperature regulator 161 so that the ink temperature T1 is equal to or higher than the printable lower limit temperature and lower than the upper limit temperature. For example, the temperature control unit 70 b performs a warm-up operation for heating the ink circulated in the ink circulation path 157 by the heating unit of the temperature regulator 161.

  The liquid level control unit 70c controls the liquid level based on the liquid level mode set by the mode setting unit 70a.

  Specifically, the liquid level control unit 70c sets the liquid levels in the upper ink tank 153 and the lower ink tank 159 as the first liquid level when the liquid level mode is set to the first liquid level mode by the mode setting unit 70a. Control to be. Further, the liquid level control unit 70c, when the liquid level mode is set to the second liquid level mode by the mode setting unit 70a, causes the ink circulation total amount to circulate through the ink circulation path 157 by ejecting ink to the inkjet head 110. The liquid level of the upper ink tank 153 and the lower ink tank 159 is controlled to be the second liquid level.

  Here, the total ink circulation amount is the total amount of ink circulating in the ink circulation path 157, the ink amount in the ink circulation path 157, the ink amount stored in the upper ink tank 153, the ink amount in the inkjet head unit 30. The amount of ink, the amount of ink stored in the lower ink tank 159, the amount of ink in the pump 160, and the amount of ink in the temperature regulator 161 are calculated.

  The first thermometer 91 is provided on the ink circulation path 157, and detects the ink temperature T1 of the ink IK flowing in the ink circulation path 157.

  The second thermometer 92 is provided outside the housing of the inkjet printing apparatus 1 and detects the environmental temperature T2 around the inkjet printing apparatus 1.

  The control unit 80 includes a temperature storage unit 81, a control unit 82, and a battery 83.

  The temperature storage unit 81 stores the ink temperature T1 detected by the first thermometer 91 and the ambient temperature T2 around the inkjet printing apparatus 1 detected by the second thermometer 92 together with the measured time.

  The control unit 82 has a clock inside, and the ink jet printing apparatus 1 detected by the time measured by the clock, the ink temperature T1 detected by the first thermometer 91, and the second thermometer 92. The temperature is stored in the temperature storage unit 81 as temperature history information in association with the ambient environmental temperature T2.

  The battery 83 supplies power so that the control unit 82 can operate even when the main power supply is off, that is, when the power supply from the power supply unit 50 is stopped.

<Operation of Inkjet Printing Apparatus 1>
Next, the operation of the inkjet printing apparatus 1 according to one embodiment of the present invention will be described.

  The ink jet printing apparatus 1 according to an embodiment of the present invention mainly executes a startup process, a printing process, a liquid level control process, and an ink temperature control process. Therefore, each process will be described in detail below.

≪Startup process≫
Details of the startup process in the inkjet printing apparatus 1 according to the embodiment of the present invention will be described.

  FIG. 3 is a flowchart showing the processing procedure of the startup process in the inkjet printing apparatus 1 according to the embodiment of the present invention.

  As shown in FIG. 3, when the power is turned on (step S101), the control unit 70 determines whether or not a predetermined time has elapsed since the previous printing (step S103). Specifically, based on the printing operation history information stored in the hard disk 72, the control unit 70 determines whether or not the elapsed time from the time when the printing process was last executed is equal to or longer than a predetermined time. To do.

  When it is determined in step S103 that the specified time or more has elapsed since the previous printing (in the case of YES), the control unit 70 executes a head cleaning process (step S105). For example, the control unit 70 ejects a small amount of ink so as not to clog the nozzles of each ink jet head 110, removes dust or the like adhering to the nozzle surface with a wiper, or excites the cleaning liquid with ultrasonic waves to generate nozzle surfaces. The nozzle surface is cleaned by spraying on the nozzle.

  Next, the mode setting unit 70a of the control unit 70 determines whether or not the ink temperature T1 has become equal to or lower than the first threshold Th1 after a predetermined time, for example, after the previous printing. (Step S107). Specifically, the mode setting unit 70 a uses the temperature history information stored in the temperature storage unit 81 based on the printing operation history information stored in the hard disk 72 to determine the ink temperature from when the printing process was last performed. Whether or not the ink temperature is equal to or lower than the first threshold Th1 is determined. Here, the first threshold value Th1 is an ink temperature set in advance so that the time from the start to the completion of the warm-up operation does not cause stress for the user, and is set to 15 (° C.), for example. .

  If it is determined in step S107 that the ink temperature T1 has not become equal to or lower than the first threshold value Th1 since the previous printing (in the case of NO), the mode setting unit 70a, for example, after a time point that is a predetermined time later, Then, it is determined whether or not the environmental temperature T2 has become equal to or lower than the second threshold Th2 after the previous printing (step S109). Specifically, the mode setting unit 70a uses the temperature history information stored in the temperature storage unit 81 based on the printing operation history information stored in the hard disk 72, and the environmental temperature from when the printing process was last performed. It is determined whether T2 includes an environmental temperature T2 that is equal to or lower than the second threshold Th1. Here, the second threshold Th2 is a temperature of the ink set in advance so that the time from the start to the completion of the warm-up operation does not cause stress for the user, and is set to 13 (° C.), for example. .

  If it is determined in step S109 that the environmental temperature T2 has not become equal to or lower than the second threshold Th2 after the previous printing (NO), the mode setting unit 70a starts the warm-up operation for a long time. It is determined whether or not a predetermined time has elapsed (step S111).

  Specifically, the mode setting unit 70a previously determines the elapsed time from the last execution of the warm-up operation for a time exceeding the predetermined time R1 based on the warm-up operation history information stored in the hard disk 72. It is determined whether or not the predetermined time R2 is exceeded. Here, the predetermined time R1 is set in advance as a time (for example, 5 (minutes)) in which the time from the start to the completion of the warm-up operation is not stressed for the user, and the predetermined time R2 is, for example, 7 ( Day).

  When it is determined in step S111 that the predetermined time has not elapsed since the previous warm-up operation (in the case of NO), the mode setting unit 70a determines whether or not it is within the set date and time range (step S113). . Specifically, the mode setting unit 70a determines whether or not the current date is within the period for performing the liquid level control in the second liquid level mode, based on the environmental temperature information stored in the hard disk 72.

  In step S113, when it is determined that it is out of the set date and time range (in the case of NO), the mode setting unit 70a sets the liquid level mode to the first liquid level mode (step S117).

  On the other hand, when it is determined as YES in steps S107 to S113, the mode setting unit 70a sets the liquid level mode to the second liquid level mode (step S115).

  The mode setting unit 70a stores the set liquid level mode in the hard disk 72 (step S119).

  Next, the temperature control unit 70b of the control unit 70 performs a warm-up operation (step S121). Specifically, the temperature controller 70b causes the temperature controller 161 to heat until the ink temperature T1 detected by the first thermometer 91 exceeds 35 (° C.).

  Then, the temperature control unit 70b stores the operation history of the warm-up operation as warm-up operation history information (step S123). Specifically, the temperature control unit 70b stores the start date / time and end date / time of the warm-up operation in the hard disk 72 as warm-up operation history information.

  As described above, according to the inkjet printing apparatus 1 according to the embodiment of the present invention, the liquid level mode is set to one of the first liquid level mode and the second liquid level mode based on the information related to the viscosity of the ink. It can be set appropriately.

≪Print processing≫
Details of the printing process in the inkjet printing apparatus 1 according to the embodiment of the present invention will be described.

  FIG. 4 is a flowchart showing a predetermined procedure of printing processing in the inkjet printing apparatus 1 according to the embodiment of the present invention.

  As shown in FIG. 4, the control unit 70 determines whether or not a print start is requested (step S201). Specifically, the control unit 70 determines whether or not an operation signal for requesting to start printing including a print job is supplied from the operation unit 60 by a user operation.

  If it is determined in step S201 that printing has been requested, the mode setting unit 70a of the control unit 70 reads out the liquid level mode stored in the hard disk 72 (step S203).

  Next, the mode setting unit 70a determines whether or not the liquid level mode read in step S203 is the second liquid level mode (step S205).

  When it is determined in step S205 that the read liquid level mode is the second liquid level mode (in the case of YES), the mode setting unit 70a calculates the ink usage amount U (step S207). Specifically, based on the print job supplied in step S201, the amount of ink consumed when this print job is executed is calculated as the ink usage amount U.

  Next, the mode setting unit 70a determines whether or not the ink usage amount U has exceeded the total ink circulation amount (step S209). Specifically, since the second liquid level mode is set, the mode setting unit 70a sets the ink amount when the upper ink tank 153 stores up to the second upper limit liquid level detection unit 172, and the lower ink tank 159. , The amount of ink when stored up to the second upper limit liquid level detection unit 175, the amount of ink in the ink circulation path 157, the amount of ink in the inkjet head unit 30, the amount of ink in the pump 160, and the temperature controller It is determined whether or not the ink circulation amount TU calculated in step S207 exceeds the total ink circulation amount TU, using the sum of the ink amount in 161 as the total ink circulation amount TU.

  When it is determined in step S209 that the ink usage amount U has exceeded the total ink circulation amount TU (in the case of YES), the mode setting unit 70a switches the liquid level mode (step S211). Specifically, the mode setting unit 70 a switches and sets the liquid level mode from the second liquid level mode to the first liquid level mode, and stores the set first liquid level mode in the hard disk 72.

  Next, the control unit 70 starts printing (step S213). Specifically, the control unit 70 executes the printing process by selectively ejecting the ink IK from the inkjet heads 110 onto the printing paper W. As a result, the ink amount decreases by the amount of ejected ink IK. Therefore, if the ink IK is not newly supplied from the ink bottle 151 to the lower ink tank 159, the total ink circulation amount TU decreases.

  Then, the control unit 70 stores the operation history of the printing process as printing history information (step S215). Specifically, the control unit 70 stores the start date / time and end date / time of the printing process in the hard disk 72 as print history information.

  As described above, according to the ink jet printing apparatus 1 according to an embodiment of the present invention, when the ink usage amount U exceeds the total ink circulation amount TU, the liquid level mode is changed from the second liquid level mode to the first liquid level mode. Therefore, it is possible to prevent a shortage of ink for printing a print job.

≪Liquid level control process≫
The details of the liquid level control process in the inkjet printing apparatus 1 according to the embodiment of the present invention will be described.

  FIG. 5 is a flowchart showing the processing procedure of the liquid level control processing in the inkjet printing apparatus 1 according to the embodiment of the present invention.

  As shown in FIG. 5, the control unit 70 determines whether or not a predetermined control cycle S1 has been reached (step S301). Here, the control cycle S1 is a predetermined cycle in which the liquid level is monitored while the power of the inkjet printing apparatus 1 is turned on.

  Next, when it is determined that the predetermined control cycle S1 has been reached (in the case of YES), the liquid level control unit 70c of the control unit 70 determines whether or not the liquid level of the upper ink tank 153 is equal to or higher than the upper limit liquid level. (Step S303). Specifically, in the liquid level control unit 70c, when the set liquid level mode is the first liquid level mode, the first upper limit liquid level detection unit 171 detects the liquid level (first upper limit liquid level). If it is determined that the liquid level is higher than the upper limit liquid level and the set liquid level mode is the second liquid level mode, the second upper limit liquid level detection unit 172 detects the liquid level (second upper limit liquid level). If it is, it is determined that it is higher than the upper limit liquid level.

  When it is determined in step S303 that the liquid level in the upper ink tank 153 is less than the upper limit liquid level (in the case of NO), the liquid level control unit 70c determines whether the liquid level in the lower ink tank 159 is equal to or higher than the lower limit liquid level. Is determined (step S305). Specifically, the liquid level control unit 70c determines that the liquid level is equal to or higher than the lower limit liquid level when the lower limit liquid level detection unit 176 detects the liquid level.

  In step S305, when it is determined that the liquid level in the lower ink tank 159 is equal to or higher than the lower limit liquid level (in the case of YES), the liquid level control unit 70c activates the pump 160 (step S307). As a result, the ink IK in the lower ink tank 159 is sent out by the pump 160 and supplied to the upper ink tank 153 via the temperature regulator 161.

  On the other hand, when it is determined in step S303 that the liquid level in the upper ink tank 153 is equal to or higher than the upper limit liquid level (in the case of YES), the liquid level control unit 70c stops the pump 160 (step S309). As a result, the liquid level of the upper ink tank 153 can be controlled to be the upper limit liquid level.

  In Step S305, when it is determined that the liquid level in the lower ink tank 159 is lower than the lower limit liquid level (in the case of NO), the liquid level control unit 70c turns on the third electromagnetic valve 152 (Step S311). ). As a result, the ink IK stored in the ink bottle 151 is supplied to the lower ink tank 159.

  Next, the liquid level control unit 70c determines whether or not the liquid level in the lower ink tank 159 is equal to or higher than the upper limit liquid level (step S313). Specifically, in the liquid level control unit 70c, when the set liquid level mode is the first liquid level mode, the first upper limit liquid level detection unit 174 detects the liquid level (first upper limit liquid level). If it is determined that the liquid level is higher than the upper limit liquid level and the set liquid level mode is the second liquid level mode, the second upper limit liquid level detection unit 175 detects the liquid level (second upper limit liquid level). If it is, it is determined that it is higher than the upper limit liquid level.

  Then, the liquid level control unit 70c determines whether or not the elapsed time from the time when the third electromagnetic valve 152 is turned on has passed the predetermined time R3 (step S315).

  When it is determined in step S315 that the elapsed time has passed the predetermined time R3 (in the case of YES), the liquid level control unit 70c is stored in the ink bottle 151 on the display / input panel 61 of the operation unit 60. An “no ink display” indicating that the ink IK has run out is displayed.

  Next, the liquid level control unit 70c turns off the third electromagnetic valve 152 (step S319). As a result, the supply of the ink IK stored in the ink bottle 151 to the lower ink tank 159 is stopped.

  As described above, according to the ink jet printing apparatus 1 according to the embodiment of the present invention, when the second liquid level mode is set, the ink is ejected to the ink jet head 110 by executing the printing process. In addition, by controlling the liquid levels of the upper ink tank 153 and the lower ink tank 159 to be the second upper limit liquid level, the ink circulation path 157 is circulated without newly providing a hardware device other than the thermometer. Reduce the total amount of ink circulating. Thus, when the total amount of ink circulation is small, the temperature of the ink is likely to rise, so that the time until the warm-up operation is completed can be shortened.

≪Ink temperature control processing≫
Details of the ink temperature control process in the inkjet printing apparatus 1 according to the embodiment of the present invention will be described.

  FIG. 6 is a flowchart showing a processing procedure of ink temperature control processing in the inkjet printing apparatus 1 according to the embodiment of the present invention.

  As shown in FIG. 6, the control unit 70 determines whether or not a predetermined control cycle S2 has been reached (step S401). Here, the control cycle S2 is a predetermined cycle in which the ink temperature is monitored while the ink jet printing apparatus 1 is powered on.

  Next, when it is determined that the predetermined control cycle S2 has been reached (in the case of YES), the temperature controller 70b of the controller 70 determines whether the ink temperature T1 detected by the first thermometer 91 is less than the lower limit temperature. It is determined whether or not (step S403). Here, the lower limit temperature is a lower limit temperature at which printing can be performed, and is set in advance to 35 (° C.), for example.

  If it is determined in step S403 that the ink temperature T1 is lower than the lower limit temperature (in the case of YES), the temperature control unit 70b stops the cooling fan of the temperature regulator 161 (step S405) and the temperature regulator 161. Heating by the heating unit is started (step S407).

  Next, the temperature controller 70b determines whether or not the ink temperature T1 detected by the first thermometer 91 has exceeded the upper limit temperature (step S409). Here, the upper limit temperature is an upper limit temperature at which printing can be performed, and is set in advance to 40 (° C.), for example.

  If it is determined in step S409 that the ink temperature T1 has exceeded the upper limit temperature (YES), the temperature control unit 70b stops heating by the heating unit of the temperature regulator 161 (step S411) and the temperature. Cooling by the cooling fan of the regulator 161 is started (step S413).

  Next, the mode setting unit 70a switches and sets the liquid level mode to the first liquid level mode (step S415), and stores the set first liquid level mode in the hard disk 72 (step S417).

  As described above, according to the inkjet printing apparatus 1 according to the embodiment of the present invention, when the ink temperature T1 exceeds the upper limit temperature, the liquid level mode is switched to the first liquid level mode. Can be prevented.

DESCRIPTION OF SYMBOLS 1 ... Inkjet printing apparatus 30 ... Inkjet head unit 50 ... Electric power supply part 60 ... Operation part 61 ... Display / input panel 70 ... Control part 70a ... Mode setting part 70b ... Temperature control part 70c ... Liquid level control part 72 ... Hard disk 73 ... RAM
DESCRIPTION OF SYMBOLS 80 ... Control unit 81 ... Temperature memory | storage part 82 ... Control part 83 ... Battery 91 ... 1st thermometer 92 ... 2nd thermometer 110 ... Inkjet head 150 ... Ink circulation path part 151 ... Ink bottle 152 ... 3rd solenoid valve 153 ... Upper ink tank 155 ... Ink supply path 156 ... Ink collection path 157 ... Ink circulation path 159 ... Lower ink tank 160 ... Pump 161 ... Temperature controller 171, 174 ... First upper limit liquid level detection unit 172, 175 ... Second Upper limit liquid level detection unit 173, 176 ... Lower limit liquid level detection unit

Claims (6)

An inkjet head that ejects ink onto a print medium;
An ink circulation path for circulating the ink between the inkjet head and an ink tank storing the ink;
Heating means for heating ink circulated in the ink circulation path;
Based on the information on the viscosity of the ink, the ink circulation amount is circulated in the ink circulation path by the heating means while reducing the total amount of ink circulation that circulates in the ink circulation path by ejecting ink with the inkjet head. Control means for performing a warm-up operation for heating the ink;
An ink jet printing apparatus comprising: The information on the viscosity of the ink is history information from a point in time that goes back a predetermined time,
The control means reduces the total amount of ink circulation that circulates through the ink circulation path by causing the inkjet head to discharge ink based on the history information, and executes the warm-up operation. The inkjet printing apparatus according to claim 1. Temperature detecting means for detecting a temperature around the ink or the inkjet printing apparatus;
First storage means for storing the temperature history detected by the temperature detection means as temperature history information;
The control means includes
In the case where the temperature from the point in time when the temperature history information is traced back for a predetermined time includes a temperature that is equal to or lower than a predetermined first threshold value, the ink circulation path is made to eject the ink by the ink jet head. The inkjet printing apparatus according to claim 2, wherein a total amount of circulating ink is reduced and the warm-up operation is executed. Second storage means for storing the operation history of the warm-up operation as operation history information;
The control means includes
Ink is ejected from the ink-jet head when the operation history from the point in time when the operation history information includes the operation history indicating that the warm-up operation has been performed for a predetermined time or more is included in the operation history. The ink-jet printing apparatus according to claim 2, wherein a total amount of ink circulating through the ink circulation path is reduced by performing the warm-up operation. Third storage means for storing temperature environment information set based on an external input;
The control means includes
2. The warm-up operation is performed while reducing the total amount of ink circulating in the ink circulation path by discharging ink with the inkjet head based on the temperature environment information. Inkjet printing device. The control means includes
The amount of ink used to print the input print job is calculated, and when the calculated ink amount exceeds the reduced total ink circulation amount, the total ink circulation amount circulating through the ink circulation path is increased. The inkjet printing apparatus according to claim 1, wherein:

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