WO2019054149A1

WO2019054149A1 - Ink jet head maintenance apparatus, ink jet recording apparatus, and ink jet head maintenance supporting method

Info

Publication number: WO2019054149A1
Application number: PCT/JP2018/031170
Authority: WO
Inventors: 和雅服部
Original assignee: 富士フイルム株式会社
Priority date: 2017-09-12
Filing date: 2018-08-23
Publication date: 2019-03-21
Also published as: JPWO2019054149A1; JP6886027B2

Abstract

Provided are an ink jet head maintenance apparatus, an ink jet recording apparatus, and an ink jet head maintenance supporting method that can warn of the occurrence of dew condensation on a nozzle surface when the temperature of a cap or a moisturizing liquid has increased. The ink jet head maintenance apparatus is provided with: a dew condensation prediction unit (644) that predicts the temperature of a cap at an arbitrary time t using a change in the temperature of the cap, and predicts a dew condensation time satisfying T(t) > Tnzl + dT, where T(t) is the predicted temperature of the cap at the arbitrary time t, Tnzl is the temperature of an ink jet head, and dt is a temperature difference derived using the temperature of the cap and the temperature of the ink jet head when dew condensation occurs in the ink jet head; and a notification unit (646) that notifies information on the predicted dew condensation time.

Description

Ink jet head maintenance device, ink jet recording device, and ink jet head maintenance support method

The present invention relates to an inkjet head maintenance device, an inkjet recording device, and an inkjet head maintenance support method, and more particularly to maintenance support for an inkjet head.

There is known an inkjet recording apparatus provided with a moisturizing unit for moisturizing the nozzle surface of the inkjet head. In an inkjet recording apparatus provided with a moisturizing unit, the moistening unit is attached to the inkjet head to moisturize the nozzle surface of the inkjet head, thereby suppressing the drying of the nozzle surface.

Patent Document 1 describes an inkjet recording apparatus that dehumidifies the vicinity of a recording head. The ink jet recording apparatus described in Patent Document 1 continuously prevents condensation on the nozzle surface of the recording head caused by a local increase in humidity caused by the vapor evaporated from the ink on the recording medium.

Patent Document 2 describes an ink jet printer provided with a cap. The printer described in Patent Document 2 includes a temperature / humidity sensor that detects the temperature and humidity of the ejection space of each head. In the printer described in Patent Document 2, the head is sealed using a cap to perform humidification maintenance, clogging of the discharge port is prevented, and the viscosity of the ink in the discharge port is in an appropriate range.

Patent Document 3 describes an inkjet recording apparatus that controls the temperature of a cap to prevent condensation on the ejection port of the recording head when the ejection port of the recording head is covered using a cap.

Patent Document 4 describes an inkjet recording apparatus provided with a cap for sealing a discharge port. In the ink jet recording apparatus described in Patent Document 4, the cap temperature is kept higher than the discharge port temperature when printing is stopped. As a result, the viscosity of the recording liquid does not increase, and high-quality recording after long periods of rest is realized.

Patent Document 5 describes a media processing apparatus provided with a head cap that covers the nozzle formation surface of an inkjet head. The media processing device described in Patent Document 5 includes a temperature sensor that detects a temperature near the inkjet head, and detects a use environment temperature near the inkjet head. Then, a threshold of the capping time is determined from the operating environment temperature, and if the capping time is equal to or higher than the threshold, condensation may occur with respect to the operating environment temperature of the inkjet head, and it is determined that the wiping step is necessary.

JP 2012-274592 A JP, 2012-158018, A Unexamined-Japanese-Patent No. 3-275359 Japanese Patent Application Laid-Open No. 6-340080 JP, 2009-12381, A

However, in a system in which the cap is used to protect the inkjet head, if the temperature inside the cap or the temperature of the moisturizer inside the cap becomes higher than the temperature of the inkjet head, condensation of the inkjet head may be concerned. When dew condensation occurs on the nozzle surface of the inkjet head, there is a possibility that the dischargeability of the inkjet head may be deteriorated.

The ink jet recording apparatus described in Patent Document 1 proposes a configuration for controlling the humidity in the vicinity of the recording head, but recording during capping when a change in the temperature of the cap and a change in the humidity of the cap occur It has not been examined for the presence of condensation on the head.

In the printer described in Patent Document 2, similarly to the ink jet recording apparatus described in Patent Document 1, a change in the temperature of the cap and a change in the humidity of the cap are examined for the presence or absence of condensation of the head during capping. It was not done.

In the ink jet recording apparatus described in Patent Document 3, the temperature obtained by subtracting the temperature of the cap from the temperature of the recording head is made constant to prevent condensation of the cap, and water droplets are prevented from adhering to the ejection surface of the recording head. . On the other hand, the ink jet recording apparatus described in Patent Document 3 needs a configuration for controlling the temperature of a cap such as a heater, and there is concern that the cap may be large and the cost may be high.

In the ink jet recording apparatus described in Patent Document 4, the cap temperature is kept higher than the discharge port temperature when printing is stopped. Then, condensation on the head may occur.

Although the media processing device described in Patent Document 5 determines whether there is a possibility that condensation will occur with respect to the use environment temperature of the ink jet head based on the environment temperature near the ink jet head, the temperature change inside the cap, or We have not studied the temperature change of the moisturizer inside the cap.

The present invention has been made in view of such circumstances, and when moistening an inkjet head using a cap, the nozzle surface is raised when the temperature rise inside the cap or the temperature rise of the moisturizing liquid inside the cap occurs. It is an object of the present invention to provide an inkjet head maintenance device, an inkjet recording device, and an inkjet head maintenance support method capable of giving notice of the occurrence of dew condensation.

The following invention aspects are provided in order to achieve the said objective.

The inkjet head maintenance device according to the first aspect comprises an inkjet head having a nozzle surface on which a nozzle opening for discharging a liquid is formed, a cap for moisturizing the inkjet head, and a temperature change of the cap at an arbitrary time t. The temperature of the cap is predicted, and the predicted temperature of the cap at an arbitrary time t is T (t), the temperature of the inkjet head is T _nzl , the temperature of the cap when condensation of the inkjet head occurs, and the condensation of the inkjet head Assuming that the temperature difference derived using the temperature of the inkjet head in the case of _{d is} dT, the condensation time which is the time t satisfying the following equation 1, T (t)> T _nzl + dT equation 1 is predicted And a notification unit for reporting information on the predicted condensation time. It is an inkjet head maintenance device.

According to the first aspect, on the basis of the predicted temperature T (t) of the cap at an arbitrary time t, the condensation time at which condensation can occur in the inkjet is predicted. This makes it possible to give notice of the occurrence of condensation of the ink jet, and makes it possible to grasp the arrangement environment of the ink jet head.

For example, when maintenance of the ink jet head is required frequently, it is possible to cope with the situation such as lowering the arrangement environment of the ink jet head.

Examples of maintenance of the ink jet head include purge for discharging the liquid from the nozzle opening and wiping for wiping the nozzle surface. The purge may be combined with processing such as preliminary ejection and a dummy jet, which operates ejection elements corresponding to the respective nozzle openings to eject the liquid from the respective nozzle openings.

An example of the inkjet head is a line-type inkjet head in which discharge ports are formed over the entire length of the medium in the medium width direction orthogonal to the medium conveyance direction. The line-type inkjet head can adopt a configuration in which a plurality of head modules are connected in the longitudinal direction of the inkjet head.

The temperature T _{nzl of the} inkjet head may be a fixed value. The temperature T _nzl of the inkjet head may use the actually measured temperature of the inkjet head, or may use the temperature setting value of the inkjet head.

As an example of the temperature difference dT, a value obtained by subtracting the temperature of the ink jet head in the case of condensation of the ink jet head from the temperature of the cap in the case of condensation of the ink jet head may be mentioned.

In the second aspect, the inkjet head maintenance device according to the first aspect may be configured to include a head temperature acquisition unit that acquires the temperature of the inkjet head.

According to the second aspect, it is possible to obtain the temperature of the inkjet head. The temperature of the inkjet head can be used to derive the predicted temperature of the cap.

The head temperature acquisition unit may detect the temperature of the inkjet head. The head temperature acquisition unit may acquire the temperature detection result of the inkjet head.

According to a third aspect, in the inkjet head maintenance device of the second aspect, the head temperature acquisition unit may be configured to include an ink temperature detection unit that detects the temperature of the ink inside the inkjet head.

According to the third aspect, the temperature of the ink inside the inkjet head can be detected. Thus, the dew condensation time can be predicted using the temperature of the ink inside the inkjet head as the temperature of the inkjet head.

According to a fourth aspect, in the inkjet head maintenance device according to the third aspect, the inkjet head includes an ink circulation channel that circulates the ink inside the inkjet head, and the ink temperature detection unit is provided in the ink circulation channel. It is also good.

According to the fourth aspect, it is possible to detect the temperature of the ink in the ink circulation channel that circulates the ink inside the inkjet head. As a result, it is possible to predict the dew condensation time by using the temperature of the ink in the ink circulation channel as the temperature of the inkjet head.

The ink jet head, which circulates the ink inside the ink jet head, is adjusted to a constant temperature.

The fifth aspect is the inkjet head maintenance device according to any one of the second aspect to the fourth aspect, wherein the head temperature acquisition unit is configured to include a head temperature detection unit that detects the temperature of the nozzle surface of the inkjet head. Good.

According to the fifth aspect, it is possible to accurately detect the temperature of the nozzle surface of the ink jet head directly linked to condensation on the nozzle surface of the ink jet head. As a result, the dew condensation time can be predicted using the temperature of the nozzle surface as the temperature of the inkjet head.

According to a sixth aspect, in the ink jet head maintenance device according to any one of the first to fifth aspects, a cap temperature detection unit that detects a temperature of the cap, and a temperature measurement of the cap detected using the cap temperature detection unit It is good also as composition provided with a cap temperature prediction part which derives prediction temperature T (t) using a value.

According to the sixth aspect, the temperature of the cap can be detected. Thereby, the temperature inside the cap can be used to derive the predicted temperature T (t).

A seventh aspect is the inkjet head maintenance device according to the sixth aspect, wherein the cap temperature prediction unit sets the temperature of the cap at the capping start time, which is the time when the cap is attached to the inkjet head, to T _0. _Assuming that the saturation temperature of T is _sat and the relaxation time at any time t is τ, the predicted temperature T (t) is expressed by the following equation 2, T (t) = T ₀ + (T _sat −T ₀ ) × {1.0-exp (-t / τ)}
The temperature prediction curve represented by equation 2 may be derived, and the condensation prediction unit may be configured to predict the condensation time using the temperature prediction curve.

According to the seventh aspect, it is possible to more accurately predict the temperature change of the cap using the temperature prediction curve. This enables more accurate prediction of condensation time.

According to an eighth aspect, in the inkjet head maintenance device according to the seventh aspect, the condensation prediction unit may be configured to derive a time corresponding to a predetermined condensation temperature threshold value in the temperature prediction curve as condensation time.

According to the eighth aspect, the dew condensation time can be derived using the temperature prediction curve and the dew condensation temperature threshold. This enables more accurate prediction of condensation time.

The ninth aspect is the inkjet head maintenance device according to the eighth aspect, wherein the dew condensation prediction unit predicts the dew condensation time with the value obtained by adding the temperature T _{nzl of the} ink jet head and the temperature difference dT as the dew condensation temperature threshold. Good.

According to the ninth aspect, it is possible to predict the dew condensation time by using a value obtained by adding the temperature T _{nzl of the} inkjet head and the temperature difference dT as the dew condensation temperature threshold.

In a tenth aspect, in the ink jet head maintenance device according to any one of the sixth to ninth aspects, the cap includes a moisturizing fluid reservoir for retaining the moisturizing fluid, and the cap temperature detection unit is a moisturizing fluid reservoir. Alternatively, the temperature of the moisturizing fluid stored in the moisturizing fluid reservoir may be detected.

According to the tenth aspect, it is possible to accurately detect the temperature of the moisturizing liquid that is directly linked to condensation on the nozzle surface of the inkjet head. Thereby, the temperature of the moisturizer can be used to derive the predicted temperature T (t).

In addition, the amount of saturated water vapor inside the cap can be grasped from the temperature of the moisturizer.

According to an eleventh aspect, in the ink jet head maintenance device according to the tenth aspect, the moisturizing fluid reservoir may be configured to retain a water-based moisturizing fluid.

According to the eleventh aspect, the aqueous moisturizer has a clear relationship between the temperature and the amount of saturated water vapor. This stabilizes the accuracy of the condensation time prediction.

According to a twelfth aspect, in the inkjet head maintenance device according to any one of the first aspect to the eleventh aspect, at least the nozzle opening forming region where the nozzle opening is formed is formed using silicon as the nozzle surface It is also good.

According to the twelfth aspect, the upper limit value of the temperature difference at which the nozzle surface does not condense can be defined.

The thirteenth aspect is the inkjet head maintenance device according to any one of the first aspect to the twelfth aspect, further comprising: a temperature difference storage unit that stores the temperature difference dT, and the dew condensation prediction unit receives the temperature difference dT from the temperature difference storage unit. It is good also as composition which acquires.

According to the thirteenth aspect, the dew condensation prediction unit can predict the dew condensation time using the temperature difference dT stored in the temperature difference storage unit.

A fourteenth aspect is the inkjet head maintenance device according to any one of the first aspect to the thirteenth aspect, wherein the condensation prediction unit generates condensation in the inkjet head when the temperature of the inkjet head is 20 ° C. or more and 35 ° C. or less The dew condensation time may be predicted by setting the temperature difference calculated by subtracting the temperature of the inkjet head from the temperature of the cap derived from the conditions to be 1.8.degree.

According to the fourteenth aspect, when the temperature of the inkjet head is 20 ° C. or more and 35 ° C. or less, the dew condensation time can be predicted by setting the temperature difference dT to 1.8 ° C.

According to a fifteenth aspect of the present invention, there is provided an ink jet recording apparatus including an ink jet head having a nozzle surface on which a nozzle opening for discharging liquid is formed, a cap for moisturizing the ink jet head, and a cap at an arbitrary time t The temperature of the cap is predicted, and the predicted temperature of the cap at any time t is T (t), the temperature of the ink jet head is T _nzl , the temperature of the cap when condensation of the ink jet head occurs, and the condensation of the ink jet head Assuming that the temperature difference derived using the temperature of the ink jet head in the case of generation is dT, the condensation time which is the time t satisfying the following equation 1, T (t)> T _nzl + dT equation 1 is predicted An ink jet comprising: a condensation prediction unit; and a notification unit for notifying information on predicted condensation time A recording device.

According to the fifteenth aspect, the same effect as the first aspect can be obtained. Moreover, based on the dew condensation time, the period to maintenance can be grasped beforehand. This makes it possible to change the print schedule, check the sample after maintenance, and the like.

In the fifteenth aspect, the same matters as the matters specified in the second to fourteenth aspects can be appropriately combined. In that case, the component carrying the process or function specified in the inkjet head maintenance device can be grasped as the component of the ink jet head printing apparatus carrying the process or function corresponding thereto.

According to a sixteenth aspect, in the inkjet recording apparatus according to the fifteenth aspect, the maintenance unit for performing the maintenance process on the inkjet head is provided, and the notification unit performs image recording when the image recording is performed at a time after the condensation time It is possible to notify maintenance notice information for giving a notice that the maintenance process is to be performed to the ink jet head using the maintenance unit before the execution of.

According to the sixteenth aspect, good discharge performance of the ink jet head can be exhibited in image recording after the condensation time.

A seventeenth aspect is the inkjet recording apparatus according to the sixteenth aspect, further comprising a maintenance control unit for controlling the maintenance unit, wherein a condensation temperature at which T ₀ is predetermined is a temperature of the cap at the capping start time when the cap is attached to the inkjet head If the threshold value is exceeded, maintenance processing may be performed on the inkjet head using the maintenance unit before the next image recording.

According to the seventeenth aspect, when condensation of the inkjet head can occur at the capping start time, maintenance is performed on the inkjet head before the next image recording. Thereby, in the next image recording, good discharge performance of the ink jet head can be exhibited.

According to an eighteenth aspect, in the ink jet recording apparatus according to any one of the fifteenth to seventeenth aspects, the notification unit includes a display unit for displaying information on condensation time, and the display unit is predetermined from the capping start time The period may be configured to display information indicating that the condensation time is being calculated.

According to the eighteenth aspect, it can be understood that the prediction accuracy of the temperature of the cap poses a practical problem for a predetermined period from the capping start time.

In the eighteenth aspect, the dew condensation time may be displayed. In the eighteenth aspect, the condensation time may be hidden.

The inkjet head maintenance support method according to the nineteenth aspect is a maintenance support method for an inkjet head including a nozzle surface on which a nozzle opening for discharging a liquid is formed, which is arbitrary using a temperature change of a cap for moisturizing the inkjet head. The temperature of the cap at time t is predicted, the predicted temperature of the cap at any time t is T (t), the temperature of the inkjet head is _Tnzl , and the temperature of the cap when condensation of the inkjet head occurs, Assuming that the temperature difference derived using the temperature of the inkjet head when condensation of the inkjet head occurs is dT, it is time t that satisfies the following equation 1, T (t)> T _nzl + dT equation 1 Provides information on the condensation prediction process for predicting condensation time and the estimated condensation time And a notification process to know the ink jet head maintenance support method.

According to the nineteenth aspect, the same effect as that of the first aspect can be obtained.

In the nineteenth aspect, the same matters as the matters specified in the second to fifteenth aspects can be combined as appropriate. In that case, the component carrying the processing or function specified in the ink jet head maintenance device can be grasped as the component of the ink jet head maintenance supporting method carrying the processing or function corresponding thereto.

According to the present invention, the condensation time at which condensation can occur in the inkjet is predicted based on the predicted temperature T (t) of the cap at an arbitrary time t. This makes it possible to give notice of the occurrence of condensation of the ink jet, and makes it possible to grasp the arrangement environment of the ink jet head.

FIG. 1 is an entire configuration view showing a schematic configuration of the ink jet printer. FIG. 2 is a perspective view showing the configuration of the tip portion of the ink jet head. FIG. 3 is a partially enlarged view of the nozzle surface. FIG. 4 is a plan view of the nozzle arrangement portion. FIG. 5 is a longitudinal sectional view showing a three-dimensional structure of the ejector. FIG. 6 is a front view schematically showing a schematic configuration of the maintenance unit. FIG. 7 is a plan view schematically showing a schematic configuration of the maintenance unit. FIG. 8 is a perspective view showing the inclined arrangement of the cap. FIG. 9 is a block diagram showing the configuration of the ink supply system and the configuration of the ink circulation system. FIG. 10 is a block diagram showing a schematic configuration of a control system. FIG. 11 is a schematic view of temperature information acquisition. FIG. 12 is a schematic view of another aspect of temperature information acquisition. FIG. 13 is a graph showing an example of a cap temperature prediction curve. FIG. 14 is a graph showing another example of a cap temperature prediction curve. FIG. 15 is a graph showing the temperature change of the cap in the uncapped state. FIG. 16 is a flow chart showing the procedure of the inkjet head maintenance support method. FIG. 17 is a flow chart showing the procedure of the cap temperature predicting step of FIG. FIG. 18 is a schematic view showing a first example of the maintenance notice screen. FIG. 19 is a schematic view showing a second example of the maintenance notice screen. FIG. 20 is a schematic view showing a third example of the maintenance notice screen. FIG. 21 is a schematic view showing a fourth example of the maintenance notice screen.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. In the present specification, the same components are denoted by the same reference numerals and redundant description will be omitted.

[Configuration Example of Inkjet Recording Apparatus]
<overall structure>
FIG. 1 is an entire configuration view showing a schematic configuration of the ink jet recording apparatus. The ink jet recording apparatus 101 shown in FIG. 1 is a sheet-fed color ink jet recording apparatus for recording a color image on a sheet P of paper.

The inkjet recording apparatus 101 includes a paper feed unit 110, a treatment liquid application unit 120, a treatment liquid drying unit 130, a drawing unit 140, an ink drying unit 150, and an accumulation unit 160. The inkjet recording apparatus 101 further includes a maintenance unit (not shown in FIG. 1). The maintenance unit is shown in FIG.

<Paper Feeder>
The sheet feeding unit 110 includes a sheet feeding device 112, a feeder board 114, and a sheet feeding drum 116. The sheet feeding device 112 takes out the sheets P set in the sheet feeding tray 112 </ b> A in the bundle state one by one in order from the top and feeds the sheet P to the feeder board 114. The feeder board 114 transfers the sheet P received from the sheet feeding device 112 to the sheet feeding drum 116.

The feed drum 116 receives the sheet P fed from the feeder board 114. The paper feed drum 116 transfers the received paper P to the treatment liquid application unit 120.

Treatment solution application section
The treatment liquid application unit 120 includes a treatment liquid application drum 122 and a treatment liquid application device 124. The treatment liquid application drum 122 is provided with a gripper 123 on the circumferential surface. The processing liquid application drum 122 grips and rotates the leading end of the sheet P using the gripper 123, and winds and transports the sheet P around its peripheral surface.

The gripper 123 includes a plurality of claws arranged along the axial direction of the treatment liquid application drum 122. The same applies to the gripper 133 of the treatment liquid drying drum 132, the gripper 143 of the drawing drum 142, and the gripper 214 of the chain delivery 210.

The treatment liquid application drum 122 receives the sheet P from the feed drum 116. The treatment liquid application drum 122 transfers the received sheet P to the treatment liquid drying unit 130.

The treatment liquid application device 124 applies the pretreatment liquid to the sheet P conveyed using the treatment liquid application drum 122. The treatment liquid application device 124 shown in FIG. 1 applies a pretreatment liquid using a roller. The application of the pretreatment liquid may use another application member such as a blade. The pretreatment liquid is a liquid having a function of aggregating, insolubilizing, or thickening the colorant components in the ink.

<Processing solution drying unit>
The treatment liquid drying unit 130 includes a treatment liquid drying drum 132 and a hot air blower 134. The treatment liquid drying drum 132 receives the sheet P from the treatment liquid application drum 122. The treatment liquid drying drum 132 transfers the received sheet P to the drawing unit 140. The treatment liquid drying drum 132 is provided with grippers 133 on its circumferential surface. The processing liquid drying drum 132 grips and rotates the leading end of the sheet P using the gripper 133 and conveys the sheet P.

The hot air blower 134 is disposed inside the treatment liquid drying drum 132. The hot air blower 134 blows hot air to the sheet P conveyed using the treatment liquid drying drum 132 to dry the pretreatment liquid.

<Drawing part>
The drawing unit 140 includes a drawing drum 142, a head unit 144, and an in-line sensor 148. The drawing drum 142 receives the sheet P from the treatment liquid drying drum 132. The drawing drum 142 transfers the received sheet P to the ink drying unit 150.

The drawing drum 142 has grippers 143 on its circumferential surface, holds the leading end of the sheet P by the gripper 143 and rotates it, and winds and transports the sheet P around the circumferential surface. The drawing drum 142 includes a suction mechanism (not shown). The drawing drum 142 sucks the sheet P wound around the circumferential surface to the circumferential surface and conveys it.

A negative pressure is used to suction the sheet P. The drawing drum 142 is provided with a plurality of suction holes on the circumferential surface. The drawing drum 142 sucks the sheet P from the inside of the drawing drum 142 through the suction holes and causes the sheet P to be attracted to the circumferential surface.

The head unit 144 includes an inkjet head 146C for ejecting cyan ink droplets, an inkjet head 146M for ejecting magenta ink droplets, an inkjet head 146Y for ejecting yellow ink droplets, and an inkjet head for ejecting black ink droplets. And 146K.

In addition, the alphabet attached to the code | symbol 146 showing an inkjet head represents the color of the ink discharged from an inkjet head. C represents cyan. M represents magenta. Y represents yellow. K represents black.

The inkjet head 146C, the inkjet head 146M, the inkjet head 146Y, and the inkjet head 146K are disposed at regular intervals on the transport path of the sheet P using the drawing drum 142.

In the present embodiment, a configuration using four color inks of cyan, magenta, yellow and black is exemplified, but the combination of the ink color and the number of colors is not limited to the present embodiment. Light ink, dark ink, and special color ink may be added as needed. For example, a configuration is possible in which ink jet heads for ejecting light-colored inks such as light cyan and light magenta are added. There is no particular limitation on the arrangement order of the inkjet heads of each color.

When ink droplets are ejected from the nozzle openings of the inkjet head 146C, the inkjet head 146M, the inkjet head 146Y, and the inkjet head 146K toward the sheet P conveyed using the drawing drum 142, an image is recorded on the sheet P Ru. The nozzle opening is illustrated in FIG. 4 with reference numeral 351.

The in-line sensor 148 illustrated in FIG. 1 reads an image recorded on the sheet P using the inkjet head 146C, the inkjet head 146M, the inkjet head 146Y, and the inkjet head 146K.

The read signal of the in-line sensor 148 is transmitted to the system controller 600 shown in FIG. The read signal of the in-line sensor 148 is used for detection of an ejection abnormal nozzle, image correction, and the like.

<Ink drying section>
The ink drying unit 150 illustrated in FIG. 1 includes a chain delivery 210, a sheet guide 220, a hot air blowing unit 230, and a sheet detection sensor 250. The chain delivery 210 receives the sheet P from the drawing drum 142. The chain delivery 210 transfers the received sheet P to the accumulation unit 160.

The chain delivery 210 comprises a pair of endless chains 212 traveling along a prescribed travel path. The pair of chains 212 comprises a plurality of grippers 214. The plurality of grippers 214 are arranged at regular intervals along the traveling direction of the chain 212.

Each gripper 214 grips the leading end of the sheet P. The chain delivery 210 uses the grippers 214 to transport the sheet P whose leading end is gripped along a prescribed transport path.

The sheet guide 220 guides the sheet P conveyed using the chain delivery 210. The sheet guide 220 shown in FIG. 1 includes a first sheet guide 222 and a second sheet guide 224.

The first sheet guide 222 guides the sheet P conveyed in the first conveyance section of the chain delivery 210. The second sheet guide 224 guides the sheet to be transported in the second transport section in the rear stage of the first transport section.

The hot air blowing unit 230 blows hot air on the sheet P conveyed using the chain delivery 210. The sheet detection sensor 250 detects the presence or absence of the sheet P. The sheet detection signal output from the sheet detection sensor 250 is transmitted to the system controller 600 shown in FIG.

The sheet detection signal is used for control of the chain delivery 210, control of the hot air blowing unit 230, and the like. In FIG. 10, the paper detection sensor 250 is not shown. Examples of the paper detection sensor 250 include a reflective optical sensor or a transmissive optical sensor.

<Accumulation unit>
The accumulation unit 160 includes an accumulation device 162. The accumulation device 162 includes an accumulation tray 162A. The accumulation device 162 receives the paper P released from the chain delivery 210. The stacking device 162 stacks the sheets P in a bundle on the stacking tray 162A.

Maintenance section
The inkjet recording apparatus 101 shown in FIG. 1 includes a maintenance unit not shown in FIG. The maintenance unit performs maintenance processing on the inkjet head 146C, the inkjet head 146M, the inkjet head 146Y, and the inkjet head 146K. Details of the maintenance unit will be described later.

[Configuration example of inkjet head]
<overall structure>
FIG. 2 is a perspective view showing the configuration of the tip portion of the ink jet head. The inkjet head 146C, the inkjet head 146M, the inkjet head 146Y, and the inkjet head 146K illustrated in FIG. 1 can apply the same configuration.

The inkjet head 146 in the following description represents any one of the inkjet head 146C, the inkjet head 146M, the inkjet head 146Y, and the inkjet head 146K shown in FIG. 1, or a generic name of these. The same applies to ink jet heads that do not have reference numerals.

When the ink jet head 146 shown in FIG. 2 is mounted on the ink jet recording apparatus 101 shown in FIG. 1, an image with a predetermined recording resolution in one scanning for the entire recording area of the sheet in the width direction of the paper. It is a line type inkjet head having a nozzle array capable of printing. The line-type inkjet head is also referred to as a line-type inkjet head, a full-line inkjet head, or a page-wide head.

The sheet indicates the sheet P shown in FIG. Hereinafter, the sheet without the reference numeral indicates the sheet P shown in FIG. The width direction of the sheet is a direction orthogonal to the sheet conveyance direction, and is a direction parallel to the printing surface of the sheet. Hereinafter, the width direction of the sheet may be described as the sheet width direction. In addition, the sheet conveyance direction may be referred to as a sheet conveyance direction. In FIG. 2, the width direction of the sheet and the conveyance direction of the sheet are not shown. The sheet width direction is illustrated in FIG. The sheet conveyance direction is illustrated in FIG.

The tip portion of the inkjet head 146 has a nozzle surface 146A. The nozzle surface 146A is formed with a nozzle opening of a nozzle for ejecting ink. The tip end portion of the inkjet head 146 includes the end of the inkjet head 146 on which the ink is ejected.

In addition, the inkjet head 146 has a structure in which a plurality of head modules 147-i are connected in a line along the longitudinal direction. Here, i is an integer from 1 to m. m is an integer representing the total number of head modules 147-i.

The longitudinal direction of the inkjet head 146 is parallel to the sheet width direction and the rotational axis direction of the drawing drum 142 shown in FIG. 1 when the inkjet head 146 is mounted on the inkjet recording apparatus 101 shown in FIG. is there. Here, as a result of including an error such as a mounting error of the ink jet head 146, the parallel may include the case of being strictly non-parallel.

The plurality of head modules 147-i are attached to and integrated with the support frame 310. The components denoted by reference numeral 309 in FIG. 2 are cables for electrical connection attached to each head module 147-i. The cable 309 transmits the electrical signal and the electrical energy transmitted to each head module 147-i.

<Configuration of nozzle face>
FIG. 3 is a partially enlarged view of the nozzle surface. The planar shape of the nozzle surface 146A-1, the nozzle surface 146A-2, and the nozzle surface 146A-3 shown in FIG. 3 is a parallelogram. Wing portions 311 are attached to both ends of the support frame 310. One end of the support frame 310 is shown in FIG. 3 and the other end is not shown.

A band-shaped nozzle arrangement portion 312-1 is provided at a central portion of the nozzle surface 146A-1 in the short direction of the head module 147-1. The nozzle placement portion 312-1 has a nozzle opening.

Similarly, a band-shaped nozzle arrangement portion 312-2 is provided at the central portion of the nozzle surface 146A-2 in the lateral direction of the head module 147-2. The nozzle placement part 312-2 has a nozzle opening. A band-shaped nozzle arrangement portion 312-3 is provided at the central portion of the nozzle surface 146A-3 in the short direction of the head module 147-3. The nozzle arrangement part 312-3 has a nozzle opening. The nozzle arrangement unit 312-1, the nozzle arrangement unit 312-2, and the nozzle arrangement unit 312-3 are examples of the nozzle opening formation region.

In FIG. 3, the nozzle openings are not shown individually but a nozzle opening row 350 composed of a plurality of nozzle openings is shown. The nozzle opening in the description of FIG. 3 may be replaced with a nozzle. Further, the nozzle opening row in the description of FIG. 3 may be replaced with a nozzle row.

<Nozzle arrangement>
FIG. 4 is a plan view of the nozzle arrangement portion. In the nozzle surface 146A-i of the head module 147-i, a two-dimensional arrangement is applied to arrange a plurality of nozzle openings 351. Reference numeral 312-i denotes a nozzle arrangement portion of the head module 147-i.

The head module 147-i has an end face on the long side along the V direction having an inclination of an angle β with respect to the paper width direction X and a W direction having an inclination of the angle α with respect to the paper conveyance direction Y It is a parallelogram planar shape having an end face on the short side.

In the head module 147-i, a plurality of nozzle openings 351 are arranged in a matrix in the row direction along the V direction and the column direction along the W direction. The nozzle openings 351 may be arranged in the row direction along the paper width direction X, and along the column direction that obliquely intersects the paper width direction X.

In the case of an inkjet head in which a plurality of nozzles are arranged in a matrix, each projected nozzle row obtained by projecting each nozzle in the matrix arrangement along the paper width direction has a nozzle density that achieves the maximum recording resolution in the paper width direction. It can be considered equivalent to a single nozzle row arranged at equal intervals. The projection nozzle array is a nozzle array obtained by orthographically projecting each nozzle in the two-dimensional nozzle array along the paper width direction.

The substantially equal intervals mean substantially equal intervals as the droplet deposition points that can be recorded in the ink jet recording apparatus. For example, the concept of equal spacing may also be included if the spacing is slightly different in consideration of manufacturing errors and / or movement of droplets on the medium due to landing interference. included. The projection nozzle row corresponds to a substantial nozzle row.

The arrangement form of the nozzles of the inkjet head is not limited, and various forms of the nozzle arrangement can be adopted. For example, instead of the form of a matrix-like two-dimensional array, a linear array of one row, a V-shaped nozzle array, and a W-shaped nozzle array having a V-shaped array as a repeating unit It is possible.

<Structure of Ejector>
FIG. 5 is a longitudinal sectional view showing a three-dimensional structure of the ejector. The ejector 22 includes a nozzle 20, a pressure chamber 50 communicating with the nozzle 20, and a piezoelectric element 52. The nozzle 20 communicates with the pressure chamber 50 through the nozzle flow channel 54. The opening at the tip of the nozzle 20 corresponds to the nozzle opening 351 shown in FIG.

The pressure chamber 50 is in communication with the supply side common branch flow path 26 via the individual supply path 24. The diaphragm 56 constituting the top surface of the pressure chamber 50 includes a conductive layer functioning as a common electrode corresponding to the lower electrode of the piezoelectric element 52. The illustration of the conductive layer is omitted.

The pressure chamber 50, the walls of the other flow path portions, the diaphragm 56 and the like are manufactured using silicon. The material of the diaphragm 56 is not limited to silicon, and a mode in which a nonconductive material such as a resin is used is also possible. The diaphragm 56 itself may be configured using a metal material such as stainless steel and may be a diaphragm that doubles as a common electrode.

A piezoelectric unimorph actuator is configured by the structure in which the piezoelectric element 52 is stacked on the vibrating plate 56. A driving voltage is applied to the individual electrode 58 which is the upper electrode of the piezoelectric element 52 to deform the piezoelectric body 60, and the diaphragm 56 is bent to change the volume of the pressure chamber 50. The pressure change associated with the volume change of the pressure chamber 50 acts on the ink, and the ink is ejected from the nozzle 20.

When the piezoelectric element 52 returns to the original state after ink ejection, the pressure chamber 50 is filled with new ink from the supply side common branch flow path 26 through the individual supply path 24. The operation in which the pressure chamber 50 is filled with ink is called refill.

The planar view shape of the pressure chamber 50 is not particularly limited, and may be in various forms such as a quadrangle or other polygons, a circle, and an ellipse. The component illustrated with reference numeral 66 in FIG. 5 is a cover plate. The cover plate 66 is a member that holds the movable space 68 of the piezoelectric element 52 and seals the periphery of the piezoelectric element 52.

Above the cover plate 66, a supply side ink chamber and a recovery side ink chamber (not shown) are formed. The supply side ink chamber is connected to a supply side common main flow path (not shown) via a communication path (not shown). The recovery side ink chamber is connected to a recovery side common main flow path (not shown) via a communication path (not shown).

The code | symbol 20A shown in FIG. 5 shows a nozzle surface. The nozzle surface 20A shown in FIG. 5 corresponds to the nozzle surface 146A shown in FIG. Further, reference numeral 21 shown in FIG. 5 represents a nozzle plate. The nozzle plate 21 is made of silicon.

[Maintenance department]
<overall structure>
FIG. 6 is a front view schematically showing a schematic configuration of the maintenance unit. FIG. 7 is a plan view schematically showing a schematic configuration of the maintenance unit. The maintenance unit 400 illustrated in FIGS. 6 and 7 performs maintenance of the inkjet head 146C, the inkjet head 146M, the inkjet head 146Y, and the inkjet head 146K illustrated in FIG. 7.

6, illustration of the inkjet head 146M, the inkjet head 146Y, and the inkjet head 146K which were shown in FIG. 7 is abbreviate | omitted, and only the inkjet head 146C is illustrated.

<Placement of Maintenance Department>
The maintenance unit 400 shown in FIG. 6 is disposed adjacent to the drawing unit 140. The maintenance unit 400 is disposed at a position adjacent to the drawing unit 140 in the rotational axis direction of the drawing drum 142. The rotational axis of the drawing drum 142 is illustrated in FIG. 6 with reference numeral 142B.

The maintenance unit 400 includes a head moving mechanism 402, a wiping unit 460, and a cap 480. The wiping unit 460 is a generic term for the wiping unit 460C, the wiping unit 460M, the wiping unit 460Y, and the wiping unit 460K illustrated in FIG. 7. Also, the cap 480 is a generic term for the cap 480C, the cap 480M, the cap 480Y, and the cap 480K.

<Head movement mechanism>
The head moving mechanism 402 shown in FIG. 6 includes a head support frame 410 and a frame transfer device 412.

The head moving mechanism 402 includes a head elevating unit (not shown). The head elevating unit raises and lowers the head support portion 414 of the ink jet head 146C in the vertical direction to raise and lower the ink jet head 146C in the vertical direction.

Similarly to the inkjet head 146C shown in FIG. 6, the inkjet head 146M, the inkjet head 146Y, and the inkjet head 146K shown in FIG. 7 are configured to be able to move up and down using a head elevating unit (not shown).

The head support frame 410 shown in FIG. 6 supports the longitudinal ends of the ink jet head 146 C via the head support portion 414. The inkjet head 146M, the inkjet head 146Y, and the inkjet head 146K shown in FIG. 7 are also supported by the head support frame 410 using a head support as in the inkjet head 146C shown in FIG.

The frame transfer device 412 includes a pair of guide rails 416 and a feed device 418. In FIG. 6, one of the pair of guide rails 416 is illustrated. The pair of guide rails 416 is disposed horizontally along the rotation axis 142 B of the drawing drum 142.

The head support frame 410 is slidably supported by the guide rails 416 via the sliders 417.

The feeding device 418 includes a feed screw 418A, a nut member 418B, and a motor 418C. The feed screw 418A is disposed horizontally along the rotation axis 142B of the drawing drum 142.

As shown in FIG. 7, the feed screw 418 A is disposed between the pair of guide rails 416. The feed screw 418A is connected to the rotation shaft of the motor 418C shown in FIG. 6 and 7, illustration of the rotation shaft of the motor 418C is omitted.

The nut member 418B is screwed into the feed screw 418A. The nut member 418 B is coupled to the head support frame 410. A motor 418C shown in FIG. 6 drives a feed screw 418A. The head moving mechanism 402 drives the motor 418C and is in the horizontal direction, and in the direction along the longitudinal direction of the inkjet head, the inkjet head 146C, the inkjet head 146M, the inkjet head 146Y, and the inkjet head 146K shown in FIG. Move together.

When the motor 418C shown in FIG. 6 is rotated forward, the head support frame 410 supporting the inkjet head 146C, the inkjet head 146M, the inkjet head 146Y, and the inkjet head 146K shown in FIG. , Moving from the drawing drum 142 toward the cap 480.

When the motor 418 C shown in FIG. 6 is reversely rotated, the head support frame 410 moves from the cap 480 toward the drawing drum 142 along the guide rails 416.

The inkjet head 146C illustrated using solid lines in FIG. 6 is the inkjet head 146C at the image recording position. The inkjet head 146C illustrated using a broken line is the inkjet head 146C at the maintenance position.

The image recording position is a position of an inkjet head capable of performing image recording on the sheet P using the inkjet head. The maintenance position is the position of the inkjet head where maintenance of the inkjet head can be performed.

<Wipe off part>
As shown in FIG. 7, the maintenance unit 400 includes a wiping unit 460C, a wiping unit 460M, a wiping unit 460Y, and a wiping unit 460K. The same configuration can be applied to the wiping unit 460C, the wiping unit 460M, the wiping unit 460Y, and the wiping unit 460K. Here, the wiping unit 460C illustrated in FIG. 6 will be described.

The wiping unit 460C is disposed in the movement path of the inkjet head 146C. The wiping unit 460C brings the wiping web 462 into contact with the nozzle surface 146A of the ink jet head 146C moving using the head moving mechanism 402, and wipes the nozzle surface 146A of the ink jet head 146C.

<cap>
As shown in FIG. 7, the maintenance unit 400 includes a cap 480C, a cap 480M, a cap 480Y, and a cap 480K. The cap 480C, the cap 480M, the cap 480Y, and the cap 480K can apply the same configuration. Here, the cap 480C will be described.

As shown in FIG. 6, the cap 480C covers the tip portion of the inkjet head 146C and seals the nozzle surface 146A of the inkjet head 146C. The cap 480 is disposed at a position opposite to the wiping portion 460C of the drawing drum 142 in the movement direction of the ink jet head 146C.

The cap 480C is provided with a moisturizing fluid reservoir that stores moisturizing fluid. Under the cap 480C, a waste tray 466 is disposed. The wiping unit 460C and the cap 480C are disposed inside the waste tray 466. The waste liquid tray 466 is connected to the waste liquid tray 466 via a waste liquid recovery pipe 467.

The moisturizer supplied to the cap 480 C, the ink purged to the cap 480 C, and the like are discharged to the waste tray 466 and recovered to the waste tank 468.

<Inclination of cap and wiping part>
FIG. 8 is a perspective view showing the inclined arrangement of the cap. The cap 480C shown in FIG. 8 is disposed to be inclined with respect to the horizontal surface, corresponding to the inclined arrangement with respect to the horizontal surface of the ink jet head 146C shown in FIG. The same applies to the cap 480M, the cap 480Y, and the cap 480K illustrated in FIG. 8.

Similar to the cap 480C, the cap 480M, the cap 480Y, and the cap 480K, the wiping unit 460C, the wiping unit 460M, the wiping unit 460Y, and the wiping unit 460K illustrated in FIG. 8 have the inkjet head 146C illustrated in FIG. The ink jet head 146Y and the ink jet head 146K are arranged to be inclined with respect to the horizontal plane, corresponding to the inclined arrangement with respect to the horizontal plane.

<Example of maintenance>
Examples of maintenance using the maintenance unit 400 include purge processing of the inkjet head and wiping processing of the nozzle surface. When the purge process is performed, processes such as preliminary ejection and a dummy jet may be used in combination.

The purge of the ink jet head is a process of applying pressure to the internal flow path of the ink jet head using a pump or the like to discharge the ink from the nozzle opening 351 shown in FIG. The preliminary ejection and the dummy jet are processes for operating the ejectors 22 provided in the respective nozzles 20 shown in FIG. 5 to eject the ink from the respective nozzles 20.

In the wiping process of the nozzle surface 146A shown in FIG. 2, the wiping web 462 shown in FIG. 7 and a wiping member such as a blade (not shown) are brought into contact with the nozzle surface 146A and the liquid adhering to the nozzle surface 146A It is a process for removing water droplets and the like caused by contamination and condensation on the nozzle surface 146A. The wiping process of the nozzle surface 146A is performed using the wiping unit 460 shown in FIG. The wiping process of the nozzle surface 146A may be referred to as wiping.

Moisturizer
As the moisturizer, a water-based moisturizer containing water as a main solvent and containing a moisturizer was applied. A humectant refers to a water-soluble compound that is low in volatility and relatively high in water retention capacity. Examples of humectants include polyols, lactams, and water soluble solid humectants. Any moisturizer can be applied as long as the surface tension of the moisturizer can be adjusted to a predetermined range.

Examples of polyols include glycerin, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, 1,3-propanediol, 1,4-butanediol, 1, 5-pentanediol, pentaerythritol and the like.

Examples of lactams include 2-pyrrolidone, N-methyl-2-pyrrolidone and the like. Examples of water-soluble solid moisturizers include nitrogen compounds such as urea, thiourea and N-ethylurea, 1,6-hexanediol, 1,8-octanediol, 2,2-dimethyl-1,3-propanediol , Diols such as 2,2-diethyl-1,3-propanediol, trimethylolethane, trimethylolpropane etc., glucose, mannose, fructose, ribose, xylose, arabinose, galactose, aldonic acid, glucitol (sorbit), maltose And monosaccharides such as cellobiose, lactose, sucrose, trehalose and maltotriose, disaccharides, oligosaccharides and polysaccharides, and derivatives of such saccharides such as reducing sugars, oxidized sugars, amino acids and thiosugars.

The moisturizing solution is preferably a polyol, more preferably glycerin, ethylene glycol, diethylene glycol or triethylene glycol, and most preferably diethylene glycol.

The content of the humectant is preferably in the range of 16% by weight or more and 30% by weight or less based on the total amount of the moisturizer. When the content of the moisturizing agent is 16% by mass or more, drying of the moisturizing liquid due to water evaporation is suppressed. When the content of the moisturizing agent is 30% by mass or less, the decrease in fluidity due to the increase in viscosity is suppressed.

<Ink supply system and ink circulation system>
FIG. 9 is a block diagram showing the configuration of the ink supply system and the configuration of the ink circulation system. In FIG. 9, some head modules 147-i among the plurality of head modules 147-i are not shown.

Each head module 147-i is connected to the supply side manifold 520 via the supply side individual flow path 500. The supply side individual flow path 500 includes a supply side damper 502 and a supply side valve 504.

Each head module 147-i is connected to the circulation side manifold 522 via the circulation side individual flow passage 510. The circulation side individual flow passage 510 includes a circulation damper 512 and a circulation side valve 514.

For convenience of illustration, in FIG. 9, the reference numerals of the head module 147-i, the supply side damper 502, the supply side valve 504, the circulation damper 512, and the circulation side valve 514 are appropriately omitted.

The supply side manifold 520 is connected to the circulation side manifold 522 via the first bypass flow path 530. Also, the supply side manifold 520 is connected to the circulation side manifold 522 via the second bypass channel 540. The first bypass passage 530 includes a first bypass valve 532. The second bypass flow path 540 includes a second bypass damper 542 and a second bypass valve 544.

The supply manifold 520 includes a supply temperature sensor 550. The circulation side manifold 522 includes a circulation side temperature sensor 552.

The supply side manifold 520 is connected to the common flow path 562 via the first supply flow path 560. The circulation side manifold 522 is connected to the common flow channel 562 via the first circulation flow channel 570. The common flow channel 562 is connected to the supply tank 590 via the direction switching valve 578 and the second supply flow channel 580.

Further, the common flow passage 562 is connected to the recovery tank 592 through the direction switching valve 578 and the second circulation flow passage 582. The supply tank 590 and the recovery tank 592 are connected via the flow path 594.

The first supply passage 560 includes a first supply back pressure tank 564 and a first supply passage valve 566. The first circulation flow path 570 includes a second supply back pressure tank 572 and a second supply flow path valve 574.

An input port 578 C of the direction switching valve 578 is connected to the common flow path 562. The first output port 578A of the direction switching valve 578 is connected to the second supply flow path 580. The second output port 578 B of the direction switching valve 578 is connected to the second circulation channel 582.

The second supply flow path 580 includes a supply pump 584. The second circulation flow path 582 includes a recovery pump 586. The flow path 594 comprises a pump 588.

The supply side manifold 520 is a flow path structure in which the ink supplied to the head module 147-i is temporarily stored inside the ink jet head 146, and is a flow path structure common to the plurality of head modules 147-i is there.

The circulation side manifold 522 is a flow path structure in which the ink recovered from the head module 147-i is temporarily stored inside the ink jet head 146, and is a flow path structure common to the plurality of head modules 147-i. is there.

The supply temperature sensor 550 detects the temperature of the ink stored in the supply manifold 520. The circulation side temperature sensor 552 detects the temperature of the ink stored in the circulation side manifold 522.

The opening and closing of the supply side valve 504, the circulation side valve 514, the first bypass valve 532, the second bypass valve 544, the first supply passage valve 566, and the second supply passage valve 574 are controlled using a valve controller (not shown) Be done. The valve control unit controls the opening and closing of valves such as the supply side valve 504 based on a command signal transmitted from the system controller shown in FIG.

The operations of the supply pump 584, the recovery pump 586, and the pump 588 are controlled using a pump control unit (not shown). The pump control unit controls the operation of a pump such as the supply pump 584 shown in FIG. 9 based on the command signal transmitted from the system controller 600 shown in FIG.

When the first supply flow path valve 566 is opened, the direction switching valve 578 is switched to the first output port 578A, and the supply pump 584 is operated, the second supply flow path 580, the common flow path 562, the first supply flow path 560 The ink is supplied from the supply tank 590 to the supply manifold 520 via the

When the second supply passage valve 574 is opened, the direction switching valve 578 is switched to the second output port 578B, and the recovery pump 586 is operated, the first circulation passage 570, the common passage 562, and the second circulation passage The ink circulates from the supply side manifold 520 to the collection tank 592 via the line 582.

When the second bypass valve 544 is opened, the ink circulates from the supply side manifold 520 to the circulation side manifold 522 via the second bypass flow path 540. When the first bypass valve 532 is opened, the ink circulates from the circulation side manifold 522 to the supply side manifold 520 via the first bypass flow path 530.

In this manner, the operation of the valves such as the supply side valve 504 and the pumps such as the supply pump 584 is appropriately controlled to supply the ink from the supply tank 590 to each head module 147-i, and each head module 147-i. The ink is circulated from i to the recovery tank 592.

The configuration of the circulation type ink jet head in which the ink inside the ink jet head is controlled to a constant temperature is not limited to the example shown in FIG. It is possible to apply the composition which can heat-control the ink inside an ink jet head to fixed temperature.

[Description of control system]
FIG. 10 is a block diagram showing a schematic configuration of a control system. The inkjet recording apparatus 101 includes a system controller 600. The system controller 600 may be configured to include a CPU (not shown), a ROM (not shown), and a RAM (not shown).

CPU is an abbreviation of Central Processing Unit. ROM is an abbreviation of Read Only Memory. RAM is an abbreviation of Random Access Memory.

A system controller 600 is an overall control unit that controls each part of the inkjet recording apparatus 101 in an integrated manner. The system controller 600 is an arithmetic unit that performs various arithmetic processes. The system controller 600 is a memory controller that controls reading and writing of data in a memory.

The inkjet recording apparatus 101 shown in FIG. 10 includes a communication unit 602 and an image memory 604. The communication unit 602 includes a communication interface (not shown). A communication unit 602 transmits and receives data to and from a host computer 603 connected to the communication interface.

The image memory 604 functions as a temporary storage unit of various data including image data. The image memory 604 reads and writes data through the system controller 600. Image data captured from the host computer 603 via the communication unit 602 is temporarily stored in the image memory 604.

The inkjet recording apparatus 101 shown in FIG. 10 includes a paper feed control unit 610, a conveyance control unit 612, a treatment liquid application control unit 616, a treatment liquid drying control unit 617, a drawing control unit 618, and a head movement control unit. An ink drying control unit 622, an accumulation control unit 624, and a maintenance control unit 626 are provided.

The paper feed control unit 610 operates the paper feed unit 110 in response to an instruction from the system controller 600. The transport control unit 612 controls the operation of the transport unit 614. The conveyance unit 614 illustrated in FIG. 10 includes the paper feed drum 116, the treatment liquid application drum 122, the drawing drum 142, and the chain delivery 210 illustrated in FIG.

The treatment liquid application control unit 616 controls the operation of the treatment liquid application unit 120 in accordance with a command from the system controller 600. The treatment liquid drying control unit 617 controls the operation of the treatment liquid drying unit 130 in accordance with a command from the system controller 600.

The drawing control unit 618 controls the operation of the drawing unit 140 in accordance with an instruction from the system controller 600. The drawing control unit 618 controls ink ejection of the inkjet head 146C, the inkjet head 146M, the inkjet head 146Y, and the inkjet head 146K illustrated in FIG. 1.

The drawing control unit 618 includes an image processing unit (not shown). The image processing unit forms dot data from input image data. The image processing unit includes a color separation processing unit (not shown), a color conversion processing unit (not shown), a correction processing unit (not shown), and a halftone processing unit (not shown).

The color separation processing unit performs color separation processing on input image data. For example, when the input image data is expressed in RGB, the input image data is decomposed into data for each of R, G, and B colors. Here, R represents red. G represents green. B represents blue.

The color conversion processing unit converts the image data of each color separated into R, G, and B into C, M, Y, K corresponding to the ink color. Here, C represents cyan. M represents magenta. Y represents yellow. K represents black.

The correction processing unit performs correction processing on the image data of each color converted into C, M, Y, and K. Examples of the correction processing include gamma correction processing, uneven density correction processing, abnormal recording element correction processing, and the like.

The halftone processing unit converts, for example, image data represented by a multi-gradation number such as 0 to 255 into binary data or dot data represented by three or more values less than the gradation number of the input image data. Convert. The halftoning unit applies a predetermined halftoning rule. Examples of halftoning rules include dithering and error diffusion.

The drawing control unit 618 includes a waveform generation unit (not shown), a waveform storage unit (not shown), and a drive circuit (not shown). The waveform generation unit generates a waveform of the drive voltage. The waveform storage unit stores the waveform of the drive voltage.

The drive circuit generates a drive voltage having a drive waveform according to the dot data. The drive circuit supplies a drive voltage to the inkjet head 146C, the inkjet head 146M, the inkjet head 146Y, and the inkjet head 146K shown in FIG.

That is, the discharge timing and the ink discharge amount of each pixel position are determined based on the dot data generated through the processing by the image processing unit. A drive voltage corresponding to the discharge timing of each pixel position and the ink discharge amount, and a control signal for determining the discharge timing of each pixel are generated. The drive voltage and the control signal are supplied to the inkjet head, and the ink ejected from the inkjet head is used to form dots on the sheet.

The head movement control unit 620 shown in FIG. 10 controls the operation of the head movement mechanism 402 shown in FIG. 6 in accordance with a command from the system controller 600. The ink drying control unit 622 illustrated in FIG. 10 controls the operation of the ink drying unit 150 in accordance with a command from the system controller 600.

The integration control unit 624 controls the operation of the integration unit 160 in response to a command from the system controller 600. Maintenance control unit 626 controls the operation of maintenance unit 400 shown in FIG. 6 in accordance with a command from system controller 600.

The inkjet recording apparatus 101 shown in FIG. 10 includes an operation unit 630 and a display unit 632. The operation unit 630 includes operation members such as operation buttons, a keyboard, and a touch panel. The operation unit 630 may include a plurality of types of operation members. In addition, illustration of the operation member is omitted.

Information input using operation unit 630 is transmitted to system controller 600. The system controller 600 generates a command signal for executing various processes according to the information transmitted from the operation unit 630. The system controller 600 transmits a command signal to a processing unit that performs various processes.

The display unit 632 includes a display device (not shown) such as a liquid crystal panel and a display driver (not shown). The display unit 632 causes the display device to display various information such as various setting information of the apparatus and abnormality information in response to an instruction from the system controller 600.

The inkjet recording apparatus 101 shown in FIG. 10 includes a parameter storage unit 634 and a program storage unit 636.

The parameter storage unit 634 stores various parameters used in the inkjet recording apparatus 101. The various parameters stored in the parameter storage unit 634 are read using the system controller 600. Various parameters are set in each part of the apparatus using the system controller 600.

The program storage unit 636 stores programs used in the respective units of the inkjet recording apparatus 101. The various programs stored in the program storage unit 636 are read via the system controller 600 and executed in the respective units of the apparatus.

The inkjet recording apparatus 101 includes a head temperature detection unit 640, a cap temperature detection unit 642, a condensation prediction unit 644, and a maintenance notification unit 646.

The head temperature detection unit 640 detects the temperature of the inkjet head. The output signal of the head temperature detection unit 640 represents the temperature of the inkjet head. An output signal of the head temperature detection unit 640 is transmitted to the condensation prediction unit 644 via the system controller 600.

As a configuration example of the head temperature detection unit 640, an aspect including a temperature sensor and a sensor circuit can be mentioned. The temperature sensor is attached to the inkjet head. The temperature sensor converts the temperature of the inkjet head into an electrical signal. As an example of a temperature sensor, the supply side temperature sensor 550 shown in FIG. 9 and the circulation side temperature sensor 552 can be mentioned.

The sensor circuit is an electrical circuit that performs signal processing on the output signal of the temperature sensor. The sensor circuit converts the output signal of the temperature sensor into a signal that can be processed by the condensation prediction unit 644. The head temperature detection unit 640 is an example of a head temperature acquisition unit that acquires the temperature of the inkjet head.

The cap temperature detection unit 642 detects the temperature of the cap. The cap temperature detection unit 642 may detect the temperature of the moisturizer accumulated in the cap instead of, or in combination with the temperature of the cap. An output signal of the cap temperature detection unit 642 is transmitted to the condensation prediction unit 644 via the system controller 600.

As a configuration example of the cap temperature detection unit 642, an aspect including a temperature sensor and a sensor circuit can be mentioned. The temperature sensor is attached to the cap. The temperature sensor converts the temperature of the cap into an electrical signal. A first temperature sensor 700 is illustrated in FIG. 11 as an example of a temperature sensor.

The dew condensation prediction unit 644 derives a predicted temperature of the cap using a change in temperature of the cap. The condensation prediction unit 644 predicts the time when condensation may occur on the inkjet head using the predicted temperature of the cap. Information on the time when condensation may occur in the inkjet head transmitted from the condensation prediction unit 644 is transmitted to the maintenance noticing unit 646 via the system controller 600. The condensation prediction unit 644 is an example of a cap temperature prediction unit.

The maintenance notifying unit 646 gives notice of the execution of the maintenance of the inkjet head based on the information of the time when the condensation may be generated in the inkjet head transmitted from the condensation predicting unit 644. The maintenance notifier 646 may use the display unit 632 to display the time when the maintenance of the inkjet head is to be performed. The maintenance notification unit 646 is an example of a notification unit that notifies information on the condensation time.

The various processing units shown in FIG. 10 may be expressed as processing units using English notation. The processor may be expressed as processor using English notation. The processing unit referred to herein includes a substantial processing unit that executes some kind of processing even if it is a component that does not use the name of the processing unit.

Various processors execute specific programs such as CPU that is a general-purpose processor that executes programs and functions as various processing units, PLD that is a processor that can change the circuit configuration after manufacturing an FPGA, etc., and ASIC, etc. For example, a dedicated electric circuit which is a processor having a circuit configuration designed specifically for the purpose. A program is synonymous with software.

FPGA is an abbreviation of Field Programmable Gate Array. PLD is an abbreviation of Programmable Logic Device. ASIC is an abbreviation of Application Specific Integrated Circuit.

One processing unit may be configured by one of these various processors, or may be configured by two or more processors of the same or different types. For example, one processing unit may be configured by combining a plurality of FPGAs or a CPU and an FPGA. In addition, a plurality of processing units may be configured using one processor.

As an example in which a plurality of processing units are configured by one processor, first, one processor is configured by a combination of one or more CPUs and software, as represented by computers such as clients and servers; There is a form in which this processor functions as a plurality of processing units.

As represented by SoC and the like, there is a form using a processor that realizes the functions of the entire system including a plurality of processing units with one IC chip. As described above, the various processing units are configured using one or more of the various processors as a hardware structure. Furthermore, the hardware-like structure of these various processors is, more specifically, an electric circuit combining circuit elements such as semiconductor elements.

Note that SoC is an abbreviation of System On Chip in English, which is system-on-chip. IC is an abbreviation of the English notation Integrated Circuit for integrated circuit. Electrical circuits are sometimes expressed as circuitry using English notation.

[Ink jet head maintenance support method]
<Overview>
Next, the inkjet head maintenance support method will be described in detail. In the following description, measures for condensation of the ink jet head will be mainly described.

As described above, when using a cap to keep the ink at a constant temperature and moisturizing the circulating inkjet head, condensation occurs in the inkjet head due to the increase in temperature of the moisturizing liquid in the cap. It can happen. As an example of condensation of the inkjet head, condensation on the nozzle surface can be mentioned.

In coping with condensation of the ink jet head according to the present embodiment, the temperature of the cap at an arbitrary time t after the capping is started is predicted. The predicted temperature of the cap at time t is T (t).

The predicted temperature T (t) of the cap can be derived using the change in temperature of the cap. The temperature change of the cap depends on the arrangement environment of the cap. Rather than determining the parameters in advance, the temperature of the cap is measured each time to derive the temperature change of the cap.

That is, the temperature change of the _cap can be derived from the temperature T _cap (t) of the cap measured based on a predetermined sampling period from time t = 0 at which capping was started.

_Let the temperature of the inkjet head be T _nzl . Let dT be the temperature difference between the cap and the inkjet head where condensation may occur on the inkjet head. As the time when condensation occurs, a time t where the predicted temperature T (t) of the cap satisfies Equation 1 below is predicted.

T (t)> T _nzl + dT formula 1
When the temperature of the ink is adjusted to a certain temperature, the temperature T _{nzl of the} inkjet head is a fixed value. The temperature T _nzl of the inkjet head may be a measured value obtained by measuring the temperature of the inkjet head. The temperature T _nzl of the inkjet head may be a temperature set value of the inkjet head.

The temperature difference dT can be an experimentally derived value based on the temperature T _{nzl of} the ink jet head where condensation of the ink jet head occurs and the temperature T _cap of the cap where condensation of the ink jet head occurs. The details of the experimentally derived temperature difference dT will be described later.

When printing is performed after time t when condensation of the ink jet head may occur, which is derived using the above equation 1, maintenance is performed at a time after time t, which is the time before printing A notice of maintenance is given to indicate that.

<Acquisition of temperature information>
FIG. 11 is a schematic view of temperature information acquisition. The temperature information here includes information on the temperature of the inkjet head 146 and information on the temperature of the cap 480. FIG. 11 shows an example in which at least one of the temperature of the ink in the supply side manifold 520 and the temperature of the ink in the circulation side manifold 522 is applied as the temperature of the ink jet head 146.

That is, using the supply side temperature sensor 550, the temperature of the ink inside the supply side manifold 520 is detected. The circulation side temperature sensor 552 is used to detect the temperature of the ink inside the circulation side manifold 522. The supply side manifold 520 and the circulation side manifold 522 are examples of components of the ink circulation flow path.

It is difficult to directly measure the temperature of the nozzle surface of the inkjet head 146. In the inkjet head 146 of the circulatory system, the temperature of the ink is controlled to a constant temperature as the entire inkjet head 146.

The nozzles in contact with the ink are formed on the nozzle plate. The nozzle plate contacts the ink at the position of the nozzle opening. Then, the temperature of the nozzle plate and the temperature of the ink can be regarded as substantially the same.

The temperature of the ink can be detected using at least one of the supply-side temperature sensor 550 and the circulation-side temperature sensor 552. The nozzle is denoted by reference numeral 20 and illustrated in FIG. The nozzle face is illustrated in FIG. 5 with reference numeral 20A. The nozzle plate is shown in FIG.

As the ink temperature, a representative value of the detection temperature of the supply-side temperature sensor 550 and the detection temperature of the circulation-side temperature sensor 552 can be employed. An average value can be adopted as a representative value. The representative value may adopt the maximum value. The representative value may adopt the minimum value. As the representative value, either one of the detection temperature of the supply side temperature sensor 550 or the detection temperature of the circulation side temperature sensor 552 may be adopted.

As the supply side temperature sensor 550 and the circulation side temperature sensor 552 shown in FIG. 11, a contact type temperature sensor can be applied. An example of a contact-type temperature sensor is a temperature sensor using a thermocouple.

A non-contact temperature sensor may be used instead of the contact temperature sensor. A contact-type temperature sensor and a non-contact-type temperature sensor may be used in combination. The same applies to the first temperature sensor 700 that detects the temperature of the cap 480, and the second temperature sensor 702 and the third temperature sensor 704 shown in FIG. The supply-side temperature sensor 550 is an example of a component of an ink temperature detection unit that detects the temperature of ink inside the inkjet head. The circulation side temperature sensor 552 is an example of a component of an ink temperature detection unit that detects the temperature of ink inside the inkjet head.

Information on the temperature of the cap 480 shown in FIG. 11 can be obtained directly using the first temperature sensor 700 attached to the cap 480. FIG. 11 illustrates an example in which the first temperature sensor 700 is disposed on the bottom surface 480A inside the cap 480.

The first temperature sensor 700 may apply a contact temperature sensor. An example of a contact-type temperature sensor is a temperature sensor using a thermocouple. The plurality of first temperature sensors 700 may be provided in the cap 480, and a representative value of temperatures detected by the plurality of temperature sensors may be the temperature of the cap 480.

FIG. 12 is a schematic view of another aspect of temperature information acquisition. FIG. 12 shows a mode in which the temperature of the surface of the wing portion 311 of the ink jet head 146 constituting the nozzle surface 146A is detected as the temperature of the ink jet head 146.

12, the second temperature sensor 702 is provided on the surface of the wing portion 311 of one end of the ink jet head 146, which constitutes the nozzle surface 146A, and the nozzle face 146A of the wing portion 311 of the other end of the ink jet head 146 is configured. In the illustrated embodiment, the third temperature sensor 704 is provided on the surface to be processed.

A representative value of the temperature detected by the second temperature sensor 702 and the temperature detected by the third temperature sensor 704 may be employed as the temperature of the inkjet head 146. The representative value may adopt the maximum value. The representative value may adopt the minimum value. The representative value may adopt either the detected temperature of the second temperature sensor 702 or the detected temperature of the third temperature sensor 704.

Either the aspect which equips only the 2nd temperature sensor 702 in the inkjet head 146, and the aspect which equips only the 3rd temperature sensor 704 in the inkjet head 146 is possible. However, from the viewpoint of securing a certain temperature detection accuracy, it is preferable to include the second temperature sensor 702 and the third temperature sensor 704. In the embodiment shown in FIG. 12, the temperature of the cap 480 is detected as in the embodiment shown in FIG. The second temperature sensor 702 and the third temperature sensor 704 are examples of components of the head temperature detection unit. The temperature of the inkjet head may be a combination of the temperature of the ink inside the inkjet head and the temperature of the surface constituting the nozzle surface of the inkjet head. For example, the temperature of the ink jet head may be the average value, the maximum value, or the minimum value of the temperature of the ink and the temperature of the surface constituting the nozzle surface.

<Acquisition of temperature difference information>
The acquisition of the temperature difference dT in the above equation 1 will be described. The temperature difference dT can be calculated by subtracting the temperature T _nzl of the inkjet head 146 from the temperature T _{cap of the} cap 480.

The temperature T _cap of the cap 480 and the temperature T _nzl of the inkjet head 146 are acquired under the condition where condensation of the inkjet head 146 occurs. The temperature T _nzl of the inkjet head 146 is subtracted from the temperature T _{cap of the} cap 480 to calculate the temperature difference dT under the condition where condensation of the inkjet head 146 occurs.

In addition, the temperature T _cap of the cap 480 and the temperature T _nzl of the inkjet head 146 are acquired under the condition where condensation of the inkjet head 146 is not generated. The temperature T _nzl of the inkjet head 146 is subtracted from the temperature T _{cap of the} cap 480 to calculate the temperature difference dT under the condition where condensation of the inkjet head 146 is not generated.

In Table 1 below, the temperature T _nzl of the ink jet head 146 is fixed at 30 ° C., and the presence or absence of dew condensation on the nozzle surface 146 A of the ink jet head 146 is shown for temperatures of four types of caps 480 near 30 ° C.

A of the presence or absence of dew condensation of the above-mentioned Table 1 represents that dew condensation does not generate | occur | produce. The presence or absence of condensation B in Table 1 above indicates that condensation occurs. According to Table 1 above, when the temperature difference dT is 1.8 ° C. or less, condensation does not occur on the nozzle surface 146A of the inkjet head 146.

When the temperature T _{cap of the} cap 480 is less than the temperature T _nzl of the inkjet head 146, the temperature difference dT is less than zero. When the temperature difference dT is less than 0, condensation does not occur on the nozzle surface 146A of the inkjet head 146. On the other hand, when the temperature difference dT exceeds 1.8 ° C., dew condensation occurs on the nozzle surface 146A of the inkjet head 146.

That is, when the temperature of the inkjet head 146 is set to 30 ° C., it is possible to predict time t at which the predicted temperature T (t) of the cap exceeds 31.8 ° C. as condensation time.

In the experiment that derived Table 1 above, the temperature T _nzl of the inkjet head 146 was fixed at 30 ° C. On the other hand, since the presence or absence of dew condensation is determined by the difference in the amount of saturated water, the temperature of the inkjet head 146 may not be fixed. The temperature of the inkjet head 146 may be detected and an actual detection value may be applied as the temperature of the inkjet head 146.

The temperature of the inkjet head is preferably 20 ° C. or more and 35 ° C. or less, which is the operating environment of a general apparatus. As the temperature difference dT when the temperature of the inkjet head is 20 ° C. or more and 35 ° C. or less, 1.8 ° C., which is the temperature difference dT when the temperature of the inkjet head is 30 ° C., may be adopted.

In deriving Table 1 above, the temperature T _cap of the _cap was detected using a first temperature sensor 700 provided on the bottom of the cap 480 shown in FIG. Further, the temperature T _nzl of the ink jet head is a measurement value of the second temperature sensor 702 provided in the wing portion 311 of the ink jet head 146. However, the measurement value of the second temperature sensor 702 is the same as the measurement value of the third temperature sensor 704.

The temperature detection of the ink jet head 146 and the temperature detection of the cap 480 may be made as long as stable detection results can be obtained, and the present invention is not limited to the above embodiment, and can be changed as appropriate.

The temperature detection of the inkjet head 146 and the temperature detection of the cap 480 do not depend on the type of inkjet head and the type of ink. It is applicable to various inkjet heads applicable to an inkjet recording device, and various inks.

The environmental temperature of the cap differs from device to device. Also, the environmental temperature of the cap differs depending on the use environment of the device. Therefore, the temperature difference dT at which condensation occurs is derived by using at least one of the identification information of the device and the environmental temperature of the cap as a parameter, and the parameter and the temperature difference dT at which condensation occurs are related to each other. You may memorize | store in a memory | storage part. Alternatively, the temperature difference dT corresponding to the parameter may be read out using the parameter as an index.

The value T _nzl + dT _obtained by adding the temperature difference dT acquired in this manner and the temperature T _nzl of the ink jet head is whether condensation of the ink jet head occurs with respect to the predicted temperature T (t) of the cap Functions as the dew condensation temperature threshold value T _th used when determining The temperature T _{nzl of the} inkjet head may be measured, and the dew condensation temperature threshold T _th may be updated each time a measured value is obtained.

Derivation of cap temperature prediction curve
Next, an aspect of deriving a cap temperature prediction curve as the predicted temperature T (t) of the cap will be described. FIG. 13 is a graph showing an example of a cap temperature prediction curve. FIG. 13 shows a temperature prediction curve 720 of the cap when the temperature of the cap at capping start time t = 0 is 28.3.degree. The capping start time t = 0 is the time when the cap is attached to the ink jet head.

The horizontal axis of the graph shown in FIG. 13 is time. “Min” shown in FIG. 13 is an abbreviation of “minutes” which is an English notation representing a minute. The same applies to min shown in FIGS. 14 and 15. The unit of the horizontal axis is minutes. The vertical axis is the temperature of the cap. The unit of the vertical axis is ° C. The environmental temperature of the cap is 27.0 ° C.

Moreover, the code _| symbol _tcon shown in FIG. 13 represents dew condensation time. The condensation time _tcon is a time when the condensation temperature threshold value _{Tth indicating the} condensation temperature is reached when the temperature prediction curve 720 is obtained. The dew condensation time t _con is a time corresponding to the intersection of the temperature prediction curve 720 and the dew condensation temperature threshold T _th .

The dots 721 illustrated around the temperature prediction curve 720 in FIG. 13 are the temperature T _cap of the _cap at each sampling timing. The same applies to the dots 723 shown in FIG. 14 and the dots 725 shown in FIG. The sampling cycle is one minute. In addition, the sampling period can apply any period from thirty seconds to one minute.

If the temperature prediction curve 720 of the cap shown in FIG. 13 is obtained, it can be predicted that the temperature of the cap reaches a temperature at which condensation of the ink jet head can occur 56 minutes after the capping start time t = 0. is there.

FIG. 14 is a graph showing another example of a cap temperature prediction curve. FIG. 14 shows a temperature prediction curve 722 of the cap when the temperature of the cap is 29.7 ° C. at the capping start time t = 0. The environmental temperature of the cap is 28.0 ° C.

If the temperature prediction curve 722 shown in FIG. 14 is obtained, it is possible to predict that the temperature of the cap will reach a temperature at which condensation of the ink jet head can occur 32 minutes after the capping start time t = 0.

Let T ₀ be the temperature of the cap at the capping start time t = 0. Let the saturation temperature of the cap be T _sat . Let relaxation time be τ. Saturation temperature T _sat can be derived using an approximate function from the measured values of the temperature T _cap of the cap at the temperature T _0, and a plurality of sampling times of the cap in the capping start time t = 0.

The relaxation time τ can be derived as a period until the tangent of the temperature prediction curve of the cap at any time t intersects a straight line representing the saturation temperature T _sat . The temperature prediction curve of the cap is expressed using Equation 2 below.

T (t) = T ₀ + (T _sat -T ₀ ) × {1.0-exp (-t / τ)} Equation 2
The saturation temperature T _sat and the relaxation time τ in Equation 2 above are updated each time a measurement of the _cap temperature T _cap is obtained. The saturation temperature T _sat and the relaxation time τ may be stored for each sampling time.

As shown in FIGS. 13 and 14, when the environmental temperature is different, the temperature change per unit period in the cap temperature prediction curve is different. For this reason, it is difficult to uniquely determine the temperature change of the cap in advance. Therefore, the temperature of the cap is sensed from the capping start time t = 0 to obtain the measured temperature value of the cap, and the predicted temperature T (t) of the cap is fitted to the above equation 2 to derive the predicted temperature curve of the cap It is possible.

FIG. 15 is a graph showing the temperature change of the cap in the uncapped state. Uncap represents that the ink jet head is separated from the cap. The uncapped state indicates a state in which the ink jet head is separated from the cap.

The horizontal axis of the graph shown in FIG. 15 represents the elapsed time from uncapping. The unit of the horizontal axis is minutes. The vertical axis of the graph shown in FIG. 15 represents the temperature of the cap. The unit of the vertical axis is ° C. As shown in FIG. 15, when the uncapping state is continued, the temperature of the cap decreases with the lapse of time from the uncapping to approach the environmental temperature.

The cap temperature curve 724 shown in FIG. 15 was derived by measuring the temperature of the cap every one minute from the uncap start time, and performing the fitting of the above equation 2 each time the measured value of the temperature of the cap was obtained.

[Procedure of inkjet head maintenance support method]
<Main flow>
FIG. 16 is a flow chart showing the procedure of the inkjet head maintenance support method. The inkjet head maintenance support method described below uses the system controller 600, the maintenance control unit 626, the head temperature detection unit 640, the cap temperature detection unit 642, the condensation prediction unit 644, the maintenance notification unit 646, etc. shown in FIG. Is executed.

In addition, the inkjet head maintenance support method may be realized by causing a computer that realizes the functions of each process to execute the program read from the program storage unit 636.

First, capping of the inkjet head is started. Examples of the capping start condition of the inkjet head include execution of purge of the inkjet head, execution of wiping of the inkjet head, temporary stop of image recording, end of image recording, and reception of a capping request of the user.

In the head initial temperature measurement step S10 shown in FIG. 16, using the head temperature detection unit 640 shown in FIG. 10, the measurement value of the temperature T _nzl of the inkjet head at the capping start time t = 0 is obtained.

In the cap initial temperature measurement step S12 shown in FIG. 16, the measured value of the temperature T _cap of the cap at the capping start time t = 0 is measured using the cap temperature detection unit 642 shown in FIG. The order of the head initial temperature measurement step S10 and the cap initial temperature measurement step S12 may be switched.

The measured values of the temperature T _nzl (t = 0) of the ink jet head at the capping start time t = 0 and the measured values of the cap temperature T _cap (t = 0) at the capping start time t = 0 have predetermined memories. It is stored in the department. Illustration of a predetermined storage unit is omitted.

After _storing the measured value of the temperature T _nzl (t = 0) of the inkjet head at the capping start time t = 0 and the measured value of the cap temperature T _cap (t = 0) at the capping start time t = 0, the temperature difference The process proceeds to calculation step S14.

The measured value of the temperature T _nzl (t = 0) of the inkjet head at the capping start time t = 0 and the measured value of the temperature T _cap (t = 0) of the cap at the capping start time t = 0 are the same storage unit May be stored. The measured value of the temperature T _nzl (t = 0) of the inkjet head at the capping start time t = 0 and the measured value of the temperature T _cap (t = 0) of the cap at the capping start time are stored in different storage units It is also good.

In the temperature difference calculation step S14, the temperature difference dT (t = 0) at the capping start time t = 0 is calculated using the condensation prediction unit 644 shown in FIG. That is, dT (t = 0) = T _cap (t = 0) -T _nzl (t = 0) is calculated.

The temperature difference dT (t = 0) at the capping start time t = 0 calculated in the temperature difference calculation step S14 shown in FIG. 16 is stored in a predetermined storage unit. The temperature difference dT (t = 0) at the capping start time t = 0 may be stored in the storage unit that stores the measured value of the temperature T _nzl (t = 0) of the inkjet head at the capping start time t = 0. Further, the temperature difference dT (t = 0) at the capping start time t = 0 and the measured value of the temperature T _nzl (t = 0) of the inkjet head at the capping start time t = 0 are stored in different storage units. It is also good.

After storing the temperature difference dT (t = 0) at the capping start time t = 0 in the temperature difference calculation step S14, the process proceeds to the initial temperature difference determination step S16. In the initial temperature difference determination step S16, the temperature difference dT (t = 0) at the capping start time t = 0 calculated in the temperature difference calculation step S14 shown in FIG. 16 using the condensation prediction unit 644 shown in FIG. However, it is determined whether the predetermined temperature difference threshold dT _th is exceeded.

The temperature difference threshold dT _th shown in FIG. 16 is the temperature difference dT used when deriving the dew condensation temperature threshold T _th . When the temperature of the inkjet head is 30 ° C., the temperature difference threshold dT _th is 1.8 ° C.

That is, in the initial temperature difference determination step S16, it is determined whether condensation of the inkjet head occurs at the capping start time t = 0. In the initial temperature difference determining step S16, the temperature difference dT in the capping start time t = 0 (t = 0) is less than or equal to the temperature difference threshold _{dT th} predetermined becomes NO determination.

If the determination is NO, the process proceeds to a cap temperature prediction step S26. Details of the cap temperature prediction step S26 will be described later. After the cap temperature prediction step S26 is completed, the process proceeds to a print command determination step S28. Details of the cap temperature prediction step S26 will be described later.

On the other hand, in the initial temperature difference determining step S16, the temperature difference dT (t = 0) in the capping start time, when exceeding the temperature difference threshold value _{dT th} predetermined becomes YES determination. If the determination is YES, the process proceeds to the first maintenance flag setting step S20.

That is, when the temperature of the cap is a temperature at which condensation of the ink jet head may occur at the capping start time, prediction of the temperature of the cap and prediction of the time when condensation of the ink jet head may occur are not performed.

In the first maintenance flag setting step S20, the maintenance control unit 626 shown in FIG. 10 sets a flag indicating non-execution of maintenance as a maintenance flag. The maintenance Flg in FIG. 16 means a maintenance flag. The maintenance Flg = 0 represents that the maintenance non-execution flag has been set. After the maintenance flag is set in the first maintenance flag setting step S20, the process proceeds to the first maintenance notification step S22.

In the first maintenance notification step S22, it is notified that maintenance will be performed before the next printing. As an example of a notice of maintenance, an example in which character information indicating that maintenance is to be performed before the next printing is performed using the display unit 632 shown in FIG. The same applies to the second maintenance notification step S50 and the third maintenance notification step S54 shown in FIG. The first maintenance notification step S22 is an example of the notification step.

In the first maintenance notification step S22 shown in FIG. 16, after notifying that maintenance will be performed before the next printing, the process proceeds to an uncap command determination step S24.

In the uncap instruction determination step S24, the maintenance control unit 626 shown in FIG. 10 determines whether or not the uncap instruction has been acquired. If the maintenance control unit 626 shown in FIG. 10 does not obtain a cap command in the uncap command determination step S24 shown in FIG. In the case of the NO determination, the maintenance control unit 626 continues the uncap instruction determination step S24 until the determination is YES in the uncap instruction determination step S24 shown in FIG.

On the other hand, when the maintenance control unit 626 shown in FIG. 10 acquires the uncap command in the uncap command determination step S24, the determination is YES. If the determination is YES, the process proceeds to the print command determination step S28 shown in FIG.

In the print command determination step S28, the drawing control unit 618 shown in FIG. 10 determines whether the print command has been acquired. If the drawing control unit 618 shown in FIG. 10 does not acquire the print command in the print command determination step S28 shown in FIG. In the case of NO determination, the maintenance control unit shown in FIG. 10 ends the inkjet maintenance support method shown in FIG.

On the other hand, if the drawing control unit 618 shown in FIG. 10 acquires the print command in the print command determination step S28, the determination is YES. In the case of a YES determination, the process proceeds to the maintenance flag determination step S30 shown in FIG.

In the maintenance flag determination step S30, the maintenance control unit 626 shown in FIG. 10 determines the presence or absence of a maintenance flag indicating execution of maintenance. The maintenance Flg = 1 shown in FIG. 16 represents that a flag indicating execution of maintenance is set.

If it is determined in the maintenance flag determination step S30 that the maintenance flag indicating execution of maintenance is not set, then NO determination is made. In the case of NO determination, the process proceeds to the printing step S34 shown in FIG.

On the other hand, when it is determined in the maintenance flag determination step S30 that the maintenance flag indicating execution of maintenance is set, YES determination is made. If the determination is YES, the process proceeds to the inkjet head maintenance step S32 shown in FIG.

In the inkjet head maintenance step S32, the maintenance control unit 626 shown in FIG. 10 performs maintenance of the inkjet head using the maintenance unit 400. After maintenance of the inkjet head is performed in the inkjet head maintenance step S32 shown in FIG. 16, the process proceeds to the printing step S34.

In the printing step S34, the maintenance control unit illustrated in FIG. 10 executes an uncap for removing the cap from the ink jet head. Next, the head movement control unit 620 moves the ink jet head to the image recording position using the head movement mechanism 402. Then, the drawing control unit 618 shown in FIG. 10 executes printing using the drawing unit 140. In the printing step S34 shown in FIG. 16, printing is performed until a predetermined print job is completed.

After the predetermined print job ends in the printing step S34, the maintenance control unit illustrated in FIG. 10 ends the inkjet maintenance support method.

<Cap temperature prediction process>
FIG. 17 is a flow chart showing the procedure of the cap temperature predicting step of FIG. In the cap temperature prediction step shown in FIG. 17, each step from the head temperature measurement step S42 to the uncap command determination step S56 is executed each time the temperature measurement of the cap is obtained. And each process from head temperature measurement process S42 to uncap command determination process S56 is repeatedly performed until it becomes YES determination in uncap command determination process S56.

In the head temperature measurement step S42, using the head temperature detection unit 640 shown in FIG. 10, _a measurement value of the temperature T _{nzl of the} inkjet head is acquired based on a predetermined sampling cycle.

The measured value of the temperature T _nzl of the inkjet head is stored in association with the information of the sampling time. The measured value of the temperature T _nzl of the inkjet head associated with the information of the sampling time is stored in a storage unit (not shown). After the temperature measurement value of the inkjet head is stored in the head temperature measurement step S42 shown in FIG. 17, the process proceeds to the cap temperature measurement step S44.

In the cap temperature measurement step S44, using the cap temperature detection unit 642 shown in FIG. 10, a measurement value of the _cap temperature T _cap is acquired based on a predetermined sampling cycle. The measured value of the _cap temperature T _cap is stored in association with the information of the sampling time.

The temperature measurement value of the cap associated with the information of the sampling time is stored in a storage unit (not shown). After the measured value of the temperature T _cap of the _cap is stored in the cap temperature measurement step S44 shown in FIG. 17, the process proceeds to the condensation time prediction step S46.

In the condensation time prediction step S46, the condensation prediction unit 644 shown in FIG. 10 is used to predict the time when condensation of the inkjet head occurs. That is, in the condensation time prediction step S46 shown in FIG. 17, the condensation prediction unit 644 shown in FIG. 10 determines the saturation temperature T in the equation 2 when the measured value of the _cap temperature T _cap is newly obtained. Update _sat and relaxation time τ, and update the cap temperature prediction curve.

Next, the condensation prediction unit 644 illustrated in FIG. 10 predicts a time that satisfies dT> dT _th using the updated cap temperature prediction curve. The temperature difference dT is calculated by subtracting the measured value of the temperature T _nzl of the inkjet head from the measured value of the temperature T _cap of the cap at each sampling time. Temperature difference threshold dT _th is applied a predetermined value.

Specifically, for each sampling time, a time corresponding to the intersection of the updated cap temperature prediction curve and the dew condensation temperature threshold T _th is derived as the dew condensation time t _con .

In condensation time predicting step S46 shown in FIG. 17, the processing proceeds to the time decision step S48 after condensation time t _con inkjet head is predicted. In time determination step S48, the maintenance notification unit 646 shown in FIG. 10 determines whether the current time exceeds the condensation time t _con . The current time here indicates each sampling time. The condensation time prediction step S46 is an example of the condensation prediction step.

If the maintenance noticing unit 646 shown in FIG. 10 determines in the time determination step S48 shown in FIG. 17 that the current time does not exceed the condensation time t _con , the determination is NO. In the case of the NO determination, the process proceeds to the second maintenance notification step S50 shown in FIG. That is, when it is determined that condensation of the inkjet head does not occur at the final sampling time, the process proceeds to the second maintenance notification step S50.

In the second maintenance notification step S50, the maintenance notification unit 646 shown in FIG. 10 performs a maintenance notification indicating that maintenance will be performed at a time after the condensation time _tcon . In the second maintenance notification step S50 shown in FIG. 17, after the maintenance notification is given, the process proceeds to an uncap command determination step S56. The second maintenance notification step S50 is an example of the notification step.

On the other hand, in the time determination step S48, when the maintenance noticing unit 646 shown in FIG. 10 determines that the current time exceeds the condensation time t _con , the determination is YES. If the determination is YES, the process proceeds to the second maintenance flag setting step S52 shown in FIG. That is, when it is determined that condensation of the inkjet head occurs at the final sampling time, the process proceeds to the second maintenance flag setting step S52.

In the second maintenance flag setting step S52, the maintenance control unit 626 shown in FIG. 10 sets a flag indicating execution of maintenance as a maintenance flag. Maintenance “Flg = 1” in FIG. 17 indicates that a flag indicating execution of maintenance is set. In the second maintenance flag setting step S52, after the maintenance flag is set, the process proceeds to the third maintenance notification step S54.

In the third maintenance notification step S54, the maintenance notification unit 646 shown in FIG. 10 executes a maintenance notification indicating that maintenance will be performed before the next printing is performed. The third maintenance notification step S54 is an example of the notification step.

In the third maintenance notification step S54 shown in FIG. 17, after the maintenance notification unit 646 shown in FIG. 10 executes the maintenance notification, the process proceeds to an uncap command determination step S56.

In the uncap instruction determination step S56, the maintenance control unit 626 shown in FIG. 10 determines whether or not the uncap instruction has been acquired. If it is determined that the maintenance control unit 626 shown in FIG. 10 has acquired the uncap instruction in the uncap instruction determination step S56 shown in FIG. 17, the determination is NO.

In the case of NO determination, each process from the head temperature measurement process S42 to the third maintenance notification process S54 is repeatedly executed until the determination is YES in the uncap command determination process S56 shown in FIG.

On the other hand, when it is determined that the maintenance control unit 626 shown in FIG. 10 does not acquire the uncap instruction in the uncap instruction determination step S56 shown in FIG. 17, the YSE determination is made. In the case of YSE determination, the cap temperature prediction step shown in FIG. 17 is ended, and the process proceeds to the print command determination step S28 shown in FIG.

[Specific example of maintenance notice]
Next, a specific example of the maintenance notice will be described with reference to FIGS. 18 to 21. The maintenance notice described below is for displaying text information using the display unit 632 shown in FIG. Text information is an example of maintenance advance information.

FIG. 18 is a schematic view showing a first example of the maintenance notice screen. The advance notice screen 740 shown in FIG. 18 is displayed on the display unit 632 when the current time is before the condensation time t _con in the time determination step S48 shown in FIG.

Hh in FIG. 18 is a numerical value representing the time at the dew condensation time. mm is a numerical value representing the minute at the condensation time. For example, when the dew condensation time is 14:25, 14:25 is displayed. It is possible to close the notice screen 740 by clicking the OK button 742 displayed on the notice screen 740.

FIG. 19 is a schematic view showing a second example of the maintenance notice screen. The notice screen 744 shown in FIG. 19 is displayed on the display unit 632 when the current time exceeds the condensation time t _con in the time determination step S48 shown in FIG. The OK button 742 shown in FIG. 19 has the same function as the OK button 742 of the preview screen 740 shown in FIG. The same applies to the OK button 742 shown in FIGS. 20 and 21.

FIG. 20 is a schematic view showing a third example of the maintenance notice screen. The notice screen 746 illustrated in FIG. 20 is a warning screen displayed on the display unit 632 when the number of samples of the temperature measurement value of the cap is small. When the number of samples of the temperature measurement of the cap is small, it means that the cap temperature prediction curve has a substantially constant slope.

That is, when the sampling cycle is one minute, it is considered that the prediction accuracy of the condensation time _tcon is low and the reliability of the condensation temperature threshold _Tth is low in the period from 1 to about 10 sampling numbers. Therefore, for the period from the sampling number 1 to the predetermined sampling number, the condensation time _tcon is displayed, and it is displayed that the condensation time _tcon is being calculated.

In the case where the sampling cycle is one minute, five minutes from the capping start time and a sufficient time from the capping start time can be mentioned as an example of a period from 1 to 10 sampling numbers.

The period for displaying the advance notice screen 746 shown in FIG. 20 can be appropriately determined based on the sampling cycle, the environmental conditions, and the like. The same applies to the case where the notice screen 748 shown in FIG. 21 is displayed.

FIG. 21 is a schematic view showing a fourth example of the maintenance notice screen. The notice screen 748 illustrated in FIG. 21 is a warning screen indicating that the condensation time _tcon is being calculated in a period from the number of samplings to 1 to a predetermined number. That is, the notice screen 748 shown in FIG. 21 makes the dew condensation time tcon _undisplayed .

Notice screen 748 shown in

notice screen

746, and 21 shown in FIG. 20, the prediction accuracy is the condensation time t _con which is a practical problem, distinguishing the condensation time t _con the prediction accuracy is not a practical problem Is possible.

A display control unit may be provided which appropriately switches the advance notice screens shown in FIGS. 18 to 21 in accordance with display conditions such as the number of samplings. For example, the notice screen 746 shown in FIG. 20 or the notice screen 748 shown in FIG. 21 is displayed for a sufficiently long time from the capping start time, and the notice screen 740 shown in FIG. May be displayed.

[Function effect]
According to the inkjet recording apparatus and the inkjet head maintenance support method configured as described above, the condensation time of the inkjet head is predicted during capping of the inkjet head, and the maintenance is notified as needed.

This makes it possible to grasp the arrangement environment state of the ink jet recording apparatus. When frequent maintenance is required, the user who is the user of the ink jet recording apparatus can take measures such as lowering the arrangement environment temperature of the ink jet recording apparatus.

It becomes possible to grasp the period up to maintenance in advance. As a result, it is possible to change the print schedule and check the printed matter after maintenance of the inkjet head.

The temperature of the ink jet head or the temperature of the ink inside the ink jet head is measured. As a result, it is possible to accurately measure the temperature in the vicinity of the nozzle that is directly connected to condensation on the nozzle surface.

Measure the temperature of the cap. As a result, it is possible to accurately measure the temperature of the moisturizer inside the cap that is directly linked to condensation on the nozzle surface. Moreover, it becomes possible to grasp the amount of saturated water vapor inside the cap from the temperature of the moisturizer.

The dew condensation time t _con of the inkjet head is predicted based on the cap temperature prediction curve derived using Equation 2 above. It is possible to grasp the situation where condensation may occur without using the measurement result of the humidity. When a water-based moisturizer is used, the relationship between the temperature and the amount of saturated water vapor is clear, and the condensation time _tcon of the inkjet head with high accuracy is predicted based on the cap temperature prediction curve derived using Equation 2 above. Is possible.

The nozzle plate 21 shown in FIG. 5 uses silicon for the nozzle surface. Thereby, it is possible to define the upper limit value of the temperature difference for preventing condensation on the nozzle surface. The temperature difference here is a value obtained by subtracting the temperature value of the nozzle surface from the temperature value of the cap.

In the present embodiment, the aspect using the aqueous ink containing water as the main component and the aqueous moisturizing liquid containing water as the main component is exemplified, but the temperature prediction of the cap and the prediction of the condensation time shown in the present embodiment Instead of using the characteristics of the water-based ink and the characteristics of the water-based moisturizing fluid, an ink other than the water-based ink and a water-warming fluid other than the water-based moisturizing fluid may be used.

[Example of application to inkjet head maintenance device]
An inkjet head maintenance device can be configured using a part of the configuration of the inkjet recording device described in the present embodiment. For example, the inkjet head 146 and maintenance unit 400 shown in FIG. 6 and the like, and the system controller 600, head movement control unit 620, maintenance control unit 626, parameter storage unit 634, program storage unit 636, head temperature shown in FIG. The inkjet head maintenance device can be configured using the detection unit 640, the cap temperature detection unit 642, the condensation prediction unit 644, the maintenance notification unit 646, and the like.

[Example of application to inkjet head maintenance program]
The inkjet head maintenance support method described in the present embodiment can be realized using a program that causes a computer to execute the functions of the respective steps. For example, the function of acquiring the temperature measurement value of the cap, the function of acquiring the temperature measurement value of the inkjet head, the function of updating the cap temperature prediction curve, the function of predicting the condensation temperature of the inkjet head based on the cap temperature prediction curve, maintenance The inkjet head maintenance support method can be realized using a program that causes a computer to execute the function of giving a notice.

[Modification of the embodiment]
In the present embodiment, the method of conveying the sheet P using the conveyance drum such as the drawing drum 142 has been exemplified, but the method of conveying the sheet P is not limited. For example, a transfer method such as a method using a transfer belt may be applied.

Although the image recording using the pretreatment liquid is exemplified in the present embodiment, the image recording may be performed without using the pretreatment liquid. Further, the configuration of the ink drying unit 150 and the configuration of the accumulation unit 160 shown in FIG. 1 are not limited to the present embodiment.

The ink drying unit 150 and the accumulation unit 160 shown in the present embodiment are not limited to the configuration shown in FIG. It is possible to apply a configuration other than the configuration shown in FIG. 1 to the transport of the sheet P, the drying process, and the stacking of the sheet P.

[About the combination of the embodiment and the modification etc.]
The components described in the above embodiments and the components described in the modification may be used in appropriate combination, and some components may be replaced.

[Explanation of terms]
Paper is an aspect of media. The medium includes those called recording paper, recording paper and the like. In addition, the medium includes a sheet-like member using a material other than paper that can record an image using ink, such as a resin sheet or a metal sheet.

Inks include liquids for graphic applications that contain colorants. The ink may include a transparent or translucent liquid containing no coloring material, and a liquid for industrial use containing resin particles, metal particles and the like.

The parallel may include substantially parallel in which two directions cross but have the same effect as the parallel.

The orthogonality is substantially parallel, which achieves the same effect as in the case where the angle formed by the two directions is 90 degrees although the angle formed by the two directions is more than 90 degrees or less than 90 degrees. It may be included.

The same may include substantially the same, which may be regarded as identical to strictly different ones.

Image recording may include concepts such as drawing, printing, and imaging. The image may include characters, figures, patterns, patterns and the like.

In the embodiment of the present invention described above, it is possible to appropriately change, add, or delete the constituent requirements without departing from the spirit of the present invention. The present invention is not limited to the embodiments described above, and many modifications can be made by those skilled in the art within the technical concept of the present invention.

Reference Signs List 20 nozzle 20A, 146A, 146A-i nozzle surface 21 nozzle plate 22 ejector 24 individual supply passage 26 supply side common branch passage 50 pressure chamber 52 piezoelectric element 54 nozzle passage 56 diaphragm 58 individual electrode 60 piezoelectric body 66 cover plate 68 movable Space 101 inkjet recording apparatus 110 paper supply unit 112 paper supply apparatus 112 A paper supply tray 114 feeder board 116 paper supply drum 120 processing liquid application unit 122 processing liquid application drum 123, 133, 143 gripper 124 processing liquid application apparatus 130 processing liquid drying unit 132 treatment liquid drying drum 134 warm air blower 140 drawing unit 142 drawing drum 142B rotary shaft 144 head unit 146, 146C, 146M, 146Y, 146K inkjet head 147-1, 147-2, 147-3, 147-i head Module 148 In-line sensor 150 Ink drying unit 160 Accumulation unit 162 Accumulator 162A Accumulation tray 210 Chain delivery 212 Chain 214 Gripper 220 Paper guide 222 First paper guide 224 Second paper guide 230 Hot air blowing unit 250 Paper detection sensor 309 Cable 310 Support Frame 311 Wing portion 312, 312-i Nozzle arrangement portion 350 Nozzle opening row 351 Nozzle opening 400 Maintenance portion 402 Head moving mechanism 410 Head support frame 412 Frame transfer device 414 Head support portion 416 Guide rail 417 Slider 418 Feed device 418A Feed screw 418B Nut member 418C Motor 460, 460C, 460M, 460Y, 460K Wiping unit 462 Wiping web 466 Waste liquid tray 467 Liquid recovery piping 468 Waste liquid tank 480, 480C, 480M, 480Y, 480K Cap 480A Bottom 500 Supply side individual flow path 502 Supply side damper 504 Supply side valve 510 Circulation side individual flow path 512 Circulation damper 514 Circulation side valve 520 Supply side manifold 522 Circulation side manifold 530 first bypass flow passage 532 first bypass valve 540 second bypass flow passage 542 second bypass damper 544 second bypass valve 550 supply side temperature sensor 552 circulation side temperature sensor 560 first supply flow passage 562 common flow passage 564 1st supply back pressure tank 566 1st supply flow path valve 570 1st circulation flow path 572 2nd supply back pressure tank 574 2nd supply flow path valve 578 direction switching valve 578A 1st output port 578B 2nd output port 578C input Mouth 580 second supply flow path 82 second circulation flow path 584 supply pump 586 recovery pump 588 pump 590 supply tank 592 recovery tank 594 flow path 600 system controller 602 communication section 603 host computer 604 image memory 610 sheet feeding control section 612 transport control section 614 transport section 616 treatment liquid Application control unit 617 Treatment liquid drying control unit 618 Drawing control unit 620 Head movement control unit 622 Ink drying control unit 624 Integration control unit 626 Maintenance control unit 630 Operation unit 632 Display unit 634 Parameter storage unit 636 Program storage unit 640 Head temperature detection unit 642 Cap temperature detection unit 644 Condensation prediction unit 646 Maintenance notification unit 700 First temperature sensor 702 Second temperature sensor 704 Third temperature sensor 720, 722 Temperature prediction curve 721, 723, 725 Dot 740 744,746,748 notice screen 742 OK button dT temperature difference _{dT th} temperature difference threshold T (t) the temperature _{T sat} saturation temperature _{T th} condensing temperature threshold value t time _{t con} condensation time of the temperature _{T nzl} inkjet head predicted temperature _{T cap} cap τ Relaxation time S10 to S56 Each step of inkjet head maintenance support method

Claims

An inkjet head having a nozzle surface on which a nozzle opening for discharging a liquid is formed;
A cap for moisturizing the inkjet head;
The temperature change of the cap is used to predict the temperature of the cap at an arbitrary time t, the predicted temperature of the cap at an arbitrary time t is T (t), the temperature of the inkjet head is Tnzl , and the inkjet When the temperature difference derived using the temperature of the cap when condensation of a head occurs and the temperature of the inkjet head when condensation of the inkjet head occurs is dT,
T (t)> T nzl + dT formula 1
A dew condensation prediction unit that predicts a dew condensation time that is a time t that satisfies
A notification unit for notifying information on the predicted dew condensation time;
Ink jet head maintenance device equipped with.
The inkjet head maintenance device according to claim 1 provided with a head temperature acquisition part which acquires the temperature of said inkjet head.
The inkjet head maintenance device according to claim 2, wherein the head temperature acquisition unit includes an ink temperature detection unit that detects the temperature of the ink inside the inkjet head.
The inkjet head includes an ink circulation channel that circulates the ink inside the inkjet head,
The inkjet head maintenance device according to claim 3, wherein the ink temperature detection unit is provided in the ink circulation channel.
The inkjet head maintenance device according to any one of claims 2 to 4, wherein the head temperature acquisition unit includes a head temperature detection unit that detects a temperature of the nozzle surface of the inkjet head.
A cap temperature detection unit that detects the temperature of the cap;
A cap temperature prediction unit that derives the predicted temperature T (t) using the measured temperature value of the cap detected using the cap temperature detection unit;
The inkjet head maintenance device according to any one of claims 1 to 5, comprising:
The cap temperature prediction unit sets the temperature of the cap at a capping start time, which is the time when the cap is attached to the ink jet head, as T 0, and sets the saturation temperature of the cap at any time t as T sat. Assuming that the relaxation time at time t is τ, the predicted temperature T (t) can be expressed by the following equation 2,
T (t) = T 0 + (T sat -T 0 ) × {1.0-exp (-t / τ)} Equation 2
Derive a temperature prediction curve expressed using
The inkjet head maintenance device according to claim 6, wherein the condensation prediction unit predicts the condensation time using the temperature prediction curve.
The inkjet head maintenance device according to claim 7, wherein the condensation prediction unit derives a time corresponding to a predetermined condensation temperature threshold value in the temperature prediction curve as the condensation time.
The inkjet head maintenance device according to claim 8, wherein the condensation prediction unit predicts the condensation time with the value obtained by adding the temperature T nzl of the inkjet head and the temperature difference dT as the condensation temperature threshold.
The cap includes a moisturizing fluid reservoir for storing a moisturizing fluid,
The ink jet head according to any one of claims 6 to 9, wherein the cap temperature detection unit is provided in the moisturizing fluid storage unit and detects the temperature of the moisturizing fluid stored in the moisturizing fluid storage unit. Maintenance equipment.
The inkjet head maintenance device according to claim 10, wherein the moisturizing fluid reservoir is stored in the moisturizing fluid reservoir.
The inkjet head maintenance device according to any one of claims 1 to 11, wherein at least a nozzle opening forming region in which the nozzle opening is formed is formed using silicon as the nozzle surface.
A temperature difference storage unit that stores the temperature difference dT;
The inkjet head maintenance device according to any one of claims 1 to 12, wherein the condensation prediction unit acquires the temperature difference dT from a temperature difference storage unit.
The condensation prediction unit is calculated by subtracting the temperature of the inkjet head from the temperature of the cap derived from the condition that causes condensation of the inkjet head when the temperature of the inkjet head is 20 ° C. or more and 35 ° C. or less The inkjet head maintenance device according to any one of claims 1 to 13, wherein the dew condensation time is predicted with a temperature difference of 1.8 ° C.
An inkjet head having a nozzle surface on which a nozzle opening for discharging a liquid is formed;
A cap for moisturizing the inkjet head;
The temperature change of the cap is used to predict the temperature of the cap at an arbitrary time t, the predicted temperature of the cap at an arbitrary time t is T (t), the temperature of the inkjet head is Tnzl , and the inkjet When the temperature difference derived using the temperature of the cap when condensation of a head occurs and the temperature of the inkjet head when condensation of the inkjet head occurs is dT,
T (t)> T nzl + dT formula 1
A dew condensation prediction unit that predicts a dew condensation time that is a time t that satisfies
A notification unit for notifying information on the predicted dew condensation time;
Inkjet recording apparatus equipped with
A maintenance unit that performs maintenance processing on the inkjet head;
When the image recording is performed at a time after the dew condensation time, the notification unit performs maintenance for giving notice that the maintenance process is to be performed on the inkjet head using the maintenance unit before the image recording is performed. The ink jet recording apparatus according to claim 15, wherein the advance notice information is notified.
A maintenance control unit that controls the maintenance unit;
When it exceeds condensation temperature threshold temperature have T 0 predetermined of the cap in the capping start time the cap to the ink jet head is mounted, prior to the next image recording, the ink jet using the maintenance unit The inkjet recording apparatus according to claim 16, wherein the maintenance process is performed on the head.
The notification unit includes a display unit that displays information on the condensation time.
The ink jet printing apparatus according to any one of claims 15 to 17, wherein the display unit displays information indicating that condensation time is being calculated, for a predetermined period from the capping start time.
A maintenance support method of an ink jet head provided with a nozzle surface in which a nozzle opening for discharging a liquid is formed,
The temperature change of the cap holding the ink jet head is used to predict the temperature of the cap at an arbitrary time t, and the predicted temperature of the cap at an arbitrary time t is T (t), and the temperature of the ink jet head is T When the temperature difference derived using the temperature of the cap when condensation occurs in the inkjet head and the temperature of the inkjet head when condensation occurs in the inkjet head is dT, Formula 1, of
T (t)> T nzl + dT formula 1
Condensation prediction step of predicting condensation time which is time t satisfying
An informing step of informing information on the predicted dew condensation time;
Inkjet head maintenance support method including: