JP7224837B2 - INKJET RECORDING DEVICE AND METHOD OF CONTROLLING INKJET RECORDING DEVICE - Google Patents

Description

The present invention relates to an inkjet recording apparatus and an inkjet recording apparatus control method.

2. Description of the Related Art There is an ink jet recording apparatus that employs an ink circulation system that circulates ink in pressure chambers communicating with ejection ports for ejecting ink. Japanese Patent Application Laid-Open No. 2002-200002 describes a technique of starting ink circulation immediately before starting image formation and stopping ink circulation when image formation is completed in a recording apparatus that employs such an ink circulation system. It is

JP 2017-121784 A

In an inkjet printing apparatus that circulates ink while a printing operation is being performed and stops the circulation when the printing operation is finished, as in the technique disclosed in Japanese Patent Laid-Open No. 2002-200314, the circulation time changes according to the content of the job. . Therefore, for example, when a job whose printing operation is completed in a short time is repeatedly input, a short-time circulating operation is repeated. If the circulation operation is repeated for a short period of time, the circulation in one circulation operation may not be sufficiently performed, and the thickened ink generated around the ejection port may not be completely flushed out. Therefore, if the circulation operation is repeated for a short period of time, there is a possibility that the thickened ink generated around the ejection port will gradually accumulate and the ejection will not be performed normally.

SUMMARY OF THE INVENTION An object of the present invention is to suppress accumulation of viscous ink generated around ejection ports.

An inkjet recording apparatus according to an aspect of the present invention includes ejection ports for ejecting ink supplied from a tank containing ink, and ejection ports provided corresponding to the ejection ports and used for ejecting liquid. an energy generating element for generating energy; and a pressure chamber located opposite the energy generating element and communicating with the ejection port and filled with the ink to be ejected from the ejection port. A recording head that performs a recording operation by ejecting ink from an outlet , circulates the ink in a circulation path including the pressure chamber when the recording operation is performed, and circulates the ink when the recording operation is completed. circulating means for stopping the recording head, adjusting means for regulating the temperature of the recording head, and control means for controlling the circulating means to stop the circulation after the circulating means continues to circulate for a predetermined time after the recording operation is finished. and wherein the control means starts adjusting the temperature when the recording operation is performed, and performs the control after stopping the temperature adjustment when the recording operation ends. and

According to the present invention, it is possible to suppress the accumulation of viscous ink generated around the ejection port.

FIG. 4 is a diagram when the recording device is in a standby state; 3 is a control configuration diagram of the recording apparatus; FIG. FIG. 4 is a diagram when the recording device is in a recording state; FIG. 10 is a diagram when the recording device is in a maintenance state; FIG. 3 is a diagram for explaining a flow channel configuration of an ink circulation system; It is a figure explaining an ejection port and a pressure chamber. It is a figure explaining a mode that thickened ink arises. 4 is a flow chart when a recording operation is performed; It is a figure which shows table information. It is a figure explaining an addition circulation sequence. It is a figure which shows table information. 4 is a flow chart when a recording operation is performed;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. It should be noted that the following embodiments do not limit the present invention, and not all combinations of features described in the embodiments are essential for the solution of the present invention. In addition, the same configuration will be described by attaching the same reference numerals. In addition, the relative arrangement, shape, etc. of the constituent elements described in the embodiments are merely examples, and are not meant to limit the scope of the present invention only to them.

<<Embodiment 1>>
FIG. 1 is an internal configuration diagram of an inkjet recording apparatus 1 (hereinafter referred to as recording apparatus 1) used in this embodiment. In the drawing, the x direction is the horizontal direction, the y direction (perpendicular to the paper surface) is the direction in which ejection ports are arranged in the recording head 8 described later, and the z direction is the vertical direction.

The recording apparatus 1 is a multi-function device including a print unit 2 and a scanner unit 3, and various processes related to recording operation and reading operation can be executed by the print unit 2 and the scanner unit 3 individually or in conjunction with each other. The scanner unit 3 includes an ADF (automatic document feeder) and an FBS (flatbed scanner), and reads documents automatically fed by the ADF and documents placed by the user on the document table of the FBS (scanning). )It can be performed. Although the present embodiment is a multifunction device having both the printing unit 2 and the scanner unit 3, a configuration without the scanner unit 3 is also possible. FIG. 1 shows the recording apparatus 1 in a standby state in which neither recording operation nor reading operation is performed.

In the printing unit 2, a first cassette 5A and a second cassette 5B for containing recording media (cut sheets) S are detachably installed at the bottom of the housing 4 in the vertical direction. The first cassette 5A accommodates relatively small recording media up to A4 size, and the second cassette 5B accommodates relatively large recording media up to A3 size in a flat stack. In the vicinity of the first cassette 5A, a first feeding unit 6A for separating and feeding the contained recording media one by one is provided. Similarly, a second feeding unit 6B is provided near the second cassette 5B. When the recording operation is performed, the recording medium S is selectively fed from one of the cassettes.

The transport roller 7, discharge roller 12, pinch roller 7a, spur 7b, guide 18, inner guide 19, and flapper 11 are a transport mechanism for guiding the recording medium S in a predetermined direction. The transport rollers 7 are drive rollers arranged upstream and downstream of the recording head 8 and driven by a transport motor (not shown). The pinch roller 7 a is a driven roller that rotates while nipping the recording medium S together with the transport roller 7 . The discharge roller 12 is a drive roller arranged downstream of the transport roller 7 and driven by a transport motor (not shown). The spur 7 b conveys the recording medium S while nipping it together with the conveying roller 7 and the discharging roller 12 arranged on the downstream side of the recording head 8 .

The guide 18 is provided on the transport path of the recording medium S and guides the recording medium S in a predetermined direction. The inner guide 19 is a member extending in the y direction and has a curved side surface, and guides the recording medium S along the side surface. The flapper 11 is a member for switching the direction in which the recording medium S is conveyed during the double-sided recording operation. The ejection tray 13 is a tray for stacking and holding the recording medium S ejected by the ejection roller 12 after the printing operation is completed.

The recording head 8 of this embodiment is a full-line type color inkjet recording head, and has a plurality of ejection openings corresponding to the width of the recording medium S along the y direction in FIG. 1 for ejecting ink according to recording data. arrayed. That is, the recording head 8 is configured to be capable of ejecting a plurality of colors of ink. When the recording head 8 is at the standby position, the ejection port surface 8a of the recording head 8 faces vertically downward and is capped by the cap unit 10 as shown in FIG. When performing a printing operation, the direction of the printing head 8 is changed by the print controller 202 to be described later so that the ejection port surface 8 a faces the platen 9 . The platen 9 is composed of a flat plate extending in the y direction, and supports the recording medium S on which the recording operation is performed by the recording head 8 from the back. The movement of the recording head 8 from the standby position to the recording position will be described later in detail.

The ink tank unit 14 stores four color inks to be supplied to the recording head 8 . The ink supply unit 15 is provided in the middle of the flow path connecting the ink tank unit 14 and the recording head 8, and adjusts the pressure and flow rate of the ink inside the recording head 8 to appropriate ranges. This embodiment employs a circulating ink supply system, and the ink supply unit 15 adjusts the pressure of the ink supplied to the recording head 8 and the flow rate of the ink recovered from the recording head 8 within appropriate ranges.

The maintenance unit 16 includes the cap unit 10 and the wiping unit 17 and activates them at predetermined timings to perform maintenance operations on the recording head 8 .

FIG. 2 is a block diagram showing a control configuration in the printing apparatus 1. As shown in FIG. The control configuration is mainly composed of a print engine unit 200 that controls the print section 2, a scanner engine unit 300 that controls the scanner section 3, and a controller unit 100 that controls the entire printing apparatus 1. FIG. The print controller 202 controls various mechanisms of the print engine unit 200 according to instructions from the main controller 101 of the controller unit 100 . Various mechanisms of the scanner engine unit 300 are controlled by the main controller 101 of the controller unit 100 . Details of the control configuration will be described below.

In the controller unit 100 , a main controller 101 composed of a CPU controls the entire printing apparatus 1 using a RAM 106 as a work area according to programs and various parameters stored in a ROM 107 . For example, when a print job is input from the host device 400 via the host I/F 102 or wireless I/F 103, the image processing unit 108 performs predetermined image processing on the received image data according to instructions from the main controller 101. Apply. Then, the main controller 101 transmits the processed image data to the print engine unit 200 via the print engine I/F 105 .

The printing apparatus 1 may acquire image data from the host apparatus 400 via wireless communication or wired communication, or may acquire image data from an external storage device (such as a USB memory) connected to the printing apparatus 1. Also good. A communication method used for wireless communication or wired communication is not limited. For example, Wi-Fi (Wireless Fidelity) (registered trademark) or Bluetooth (registered trademark) can be applied as a communication method used for wireless communication. As a communication method used for wired communication, USB (Universal Serial Bus) or the like can be applied. Also, for example, when a read command is input from the host device 400 , the main controller 101 transmits this command to the scanner section 3 via the scanner engine I/F 109 .

The operation panel 104 is a mechanism for the user to input/output to/from the printing apparatus 1 . A user can instruct operations such as copying and scanning, set a print mode, and recognize information of the printing apparatus 1 via the operation panel 104 .

In the print engine unit 200 , a print controller 202 configured by a CPU controls various mechanisms provided in the print section 2 while using a RAM 204 as a work area according to programs and various parameters stored in a ROM 203 . When various commands and image data are received via the controller I/F 201 , the print controller 202 temporarily stores them in the RAM 204 . The print controller 202 causes the image processing controller 205 to convert the stored image data into print data so that the print head 8 can be used for printing operations. When print data is generated, the print controller 202 causes the print head 8 to perform a print operation based on the print data via the head I/F 206 . At this time, the print controller 202 drives the feeding units 6A and 6B, the transport rollers 7, the ejection rollers 12, and the flapper 11 shown in FIG. In accordance with an instruction from the print controller 202, the recording operation by the recording head 8 is executed in conjunction with the conveying operation of the recording medium S, and printing processing is performed.

The head carriage control unit 208 changes the direction and position of the recording head 8 according to the operating state such as the maintenance state and recording state of the recording apparatus 1 . The ink supply control unit 209 controls the ink supply unit 15 so that the pressure of the ink supplied to the recording head 8 is within an appropriate range. The maintenance control unit 210 controls operations of the cap unit 10 and the wiping unit 17 in the maintenance unit 16 when performing maintenance operations on the recording head 8 .

In the scanner engine unit 300 , the main controller 101 controls hardware resources of the scanner controller 302 while using the RAM 106 as a work area according to programs and various parameters stored in the ROM 107 . As a result, various mechanisms provided in the scanner section 3 are controlled. For example, the main controller 101 controls the hardware resources in the scanner controller 302 via the controller I/F 301 to transport the document placed on the ADF by the user via the transport control unit 304 and read it by the sensor 305 . . The scanner controller 302 stores the read image data in the RAM 303 . The print controller 202 converts the image data acquired as described above into print data, thereby making it possible for the print head 8 to execute a print operation based on the image data read by the scanner controller 302. .

FIG. 3 shows the recording device 1 in the recording state. 1, the cap unit 10 is separated from the ejection port surface 8a of the recording head 8, and the ejection port surface 8a faces the platen 9. As shown in FIG. In this embodiment, the plane of the platen 9 is tilted about 45 degrees with respect to the horizontal direction, and the ejection port surface 8a of the recording head 8 at the recording position is also tilted horizontally so that the distance from the platen 9 is kept constant. is tilted about 45 degrees with respect to

When moving the print head 8 from the standby position shown in FIG. 1 to the print position shown in FIG. 3, the print controller 202 uses the maintenance control section 210 to lower the cap unit 10 to the retracted position shown in FIG. As a result, the discharge port surface 8a of the recording head 8 is separated from the cap member 10a. Thereafter, the print controller 202 rotates the recording head 8 by 45 degrees while adjusting the vertical height of the recording head 8 using the head carriage control unit 208 , so that the ejection port surface 8 a faces the platen 9 . When the print operation is completed and the print head 8 is moved from the print position to the standby position, the print controller 202 performs the reverse steps.

FIG. 4 is a diagram when the recording apparatus 1 is in a maintenance state. When moving the recording head 8 from the standby position shown in FIG. 1 to the maintenance position shown in FIG. 4, the print controller 202 moves the recording head 8 upward in the vertical direction and moves the cap unit 10 downward in the vertical direction. Then, the print controller 202 moves the wiping unit 17 rightward in FIG. 4 from the retracted position. After that, the print controller 202 moves the recording head 8 downward in the vertical direction to the maintenance position where the maintenance operation can be performed.

On the other hand, when moving the recording head 8 from the recording position shown in FIG. 3 to the maintenance position shown in FIG. 4, the print controller 202 moves the recording head 8 vertically upward while rotating it by 45 degrees. The print controller 202 then moves the wiping unit 17 rightward from the retracted position. After that, the print controller 202 moves the recording head 8 downward in the vertical direction to the maintenance position where the maintenance operation by the maintenance unit 16 is possible.

<Ink supply unit (circulation system)>
FIG. 5 is a diagram including the ink supply unit 15 employed in the inkjet recording apparatus 1 of this embodiment. The flow path configuration of the ink circulation system of this embodiment will be described with reference to FIG. The ink supply unit 15 supplies the ink supplied from the ink tank unit 14 to the recording head 8 (head unit). Although FIG. 6 shows the configuration for one color of ink, such a configuration is actually prepared for each ink color. The ink supply unit 15 is basically controlled by the ink supply controller 209 shown in FIG. Each configuration of the ink supply unit 15 will be described below.

Ink circulates mainly between the sub-tank 151 and the recording head 8 . In the recording head 8 , an ink ejection operation is performed based on the image data, and the ink that has not been ejected is collected again in the sub-tank 151 .

A sub-tank 151 containing a predetermined amount of ink is connected to a supply channel C2 for supplying ink to the printhead 8 and a recovery channel C4 for recovering ink from the printhead 8 . That is, the sub-tank 151, the supply channel C2, the recording head 8, and the recovery channel C4 constitute a circulation channel (circulation channel) through which the ink circulates. Further, the sub-tank 151 is connected to the flow path C0 through which air flows.

The sub-tank 151 is provided with a liquid level detection means 151a composed of a plurality of electrode pins. The ink supply control unit 209 can grasp the height of the ink liquid surface, that is, the remaining amount of ink in the sub-tank 151 by detecting the presence or absence of conduction current between the plurality of pins. The decompression pump P<b>0 (in-tank decompression pump) is a source of negative pressure for decompressing the interior of the sub-tank 151 . The atmosphere release valve V0 is a valve for switching whether or not the inside of the sub-tank 151 is communicated with the atmosphere.

The main tank 141 is a tank that stores ink to be supplied to the sub-tank 151 . The main tank 141 is composed of a flexible member, and the sub-tank 151 is filled with ink by the volume change of the flexible member. The main tank 141 is detachable from the main body of the printing apparatus. A tank supply valve V1 for switching the connection between the sub-tank 151 and the main tank 141 is arranged in the middle of the tank connection channel C1 that connects the sub-tank 151 and the main tank 141 .

When the ink supply control unit 209 detects that the ink level in the sub-tank 151 is less than a predetermined amount by the liquid level detection means 151a, the ink supply control unit 209 closes the air release valve V0, the supply valve V2, the recovery valve V4, and the head replacement valve V5. . The ink supply control unit 209 also opens the tank supply valve V1. In this state, the ink supply control unit 209 operates the decompression pump P0. Then, the inside of the sub-tank 151 becomes negative pressure, and ink is supplied from the main tank 141 to the sub-tank 151 . When the liquid level detection means 151a detects that the ink in the sub-tank 151 has exceeded a predetermined amount, the ink supply control unit 209 closes the tank supply valve V1 and stops the decompression pump P0.

The supply channel C2 is a channel for supplying ink from the sub-tank 151 to the recording head 8, and a supply pump P1 and a supply valve V2 are arranged in the middle of the supply channel C2. During the recording operation, by driving the supply pump P1 with the supply valve V2 open, the ink can be supplied to the recording head 8 and circulated in the circulation path. The amount of ink ejected per unit time by the recording head 8 varies according to image data. The flow rate of the supply pump P1 is determined so as to be able to cope with even the case where the recording head 8 performs an ejection operation in which the amount of ink consumed per unit time is maximized.

The relief channel C3 is a channel that is upstream of the supply valve V2 and connects the upstream side and the downstream side of the supply pump P1. A relief valve V3, which is a differential pressure valve, is arranged in the middle of the relief passage C3. Rather than being opened and closed by a drive mechanism, the relief valve is spring biased and configured to open when a predetermined pressure is reached. For example, when the amount of ink supplied from the supply pump P1 per unit time is larger than the total value of the discharge amount per unit time of the recording head 8 and the flow rate (ink withdrawal amount) of the recovery pump P2 per unit time. , the relief valve V3 is opened according to the pressure acting on it. As a result, a circular flow path is formed by a part of the supply flow path C2 and the relief flow path C3. By providing the configuration of the relief channel C3, the amount of ink supplied to the recording head 8 can be adjusted according to the amount of ink consumed by the recording head 8, and the pressure in the circulation path can be stabilized regardless of image data. .

The recovery channel C4 is a channel for recovering ink from the recording head 8 to the sub-tank 151, and a recovery pump P2 and a recovery valve V4 are arranged in the middle of the channel. The recovery pump P2 serves as a source of negative pressure and sucks ink from the recording head 8 when circulating the ink in the circulation path. By driving the recovery pump P2, an appropriate pressure difference is generated between the IN channel 80b and the OUT channel 80c in the recording head 8, and the ink can be circulated between the IN channel 80b and the OUT channel 80c. .

The recovery valve V4 is also a valve for preventing backflow when the recording operation is not performed, that is, when the ink is not circulated in the circulation path. In the circulation path of this embodiment, the sub-tank 151 is arranged vertically above the recording head 8 (see FIG. 1). Therefore, when the supply pump P1 and the recovery pump P2 are not driven, ink may flow back from the sub-tank 151 to the recording head 8 due to the difference in water head between the sub-tank 151 and the recording head 8 . In order to prevent such backflow, in this embodiment, a recovery valve V4 is provided in the recovery channel C4.

The supply valve V2 also functions as a valve for preventing the supply of ink from the sub-tank 151 to the recording head 8 when the recording operation is not performed, that is, when the ink is not circulated in the circulation path. .

The head replacement channel C5 is a channel that connects the supply channel C2 and an air chamber (a space in which ink is not stored) of the sub-tank 151, and a head replacement valve V5 is arranged in the middle of the channel. One end of the head replacement channel C5 is connected upstream of the recording head 8 in the supply channel C2 and connected downstream of the supply valve V2. The other end of the head replacement channel C5 is connected above the sub-tank 151 and communicates with the air chamber inside the sub-tank 151 . The head replacement flow path C5 is used when extracting ink from the recording head 8 in use, such as when replacing the recording head 8 or when transporting the recording apparatus 1 . The head replacement valve V5 is controlled by the ink supply control unit 209 so as to be closed except when the recording head 8 is filled with ink and when the ink is recovered from the recording head 8 .

Next, the configuration of the flow paths within the printhead 8 will be described. The ink supplied to the recording head 8 from the supply channel C2 passes through the filter 83 and is supplied to the first negative pressure control unit 81 and the second negative pressure control unit 82 . The control pressure of the first negative pressure control unit 81 is set to a weak negative pressure (negative pressure with a small pressure difference from the atmospheric pressure). The control pressure of the second negative pressure control unit 82 is set to a strong negative pressure (negative pressure with a large pressure difference from the atmospheric pressure). The pressures in the first negative pressure control unit 81 and the second negative pressure control unit 82 are generated within an appropriate range by driving the recovery pump P2.

In the ink ejection section 80, a plurality of recording element substrates 80a each having a plurality of ejection openings are arranged to form a long ejection opening array. A common supply channel 80b (IN channel) for guiding ink supplied from the first negative pressure control unit 81 and a common recovery channel for guiding ink supplied from the second negative pressure control unit 82 80c (OUT channel) also extends in the arrangement direction of the recording element substrates 80a. Further, individual supply channels connected to the common supply channel 80b and individual recovery channels connected to the common recovery channel 80c are formed in each recording element substrate 80a. Therefore, in each recording element substrate 80a, the ink flows in such a manner that it flows in from the common supply channel 80b with relatively weak negative pressure and flows out to the common recovery channel 80c with relatively strong negative pressure. generated. Pressure chambers that communicate with the ejection ports and are filled with ink are provided in the paths of the individual supply channels and the individual recovery channels. occurs. When an ejection operation is performed in the recording element substrate 80a, some of the ink that moves from the common supply channel 80b to the common recovery channel 80c is consumed by being ejected from the ejection openings, but the ink that has not been ejected is consumed. It moves to recovery channel C4 via common recovery channel 80c.

FIG. 6(a) is a schematic plan view enlarging a part of the recording element substrate 80a, and FIG. 6(b) is a schematic cross-sectional view taken along the cross-sectional line VIb-VIb of FIG. 6(a). The printing element substrate 80a is provided with pressure chambers 1005 filled with ink and ejection ports 1006 for ejecting ink. A recording element 1004 is provided at a position facing the ejection port 1006 in the pressure chamber 1005 . In the recording element substrate 80a, a plurality of individual supply flow paths 1008 connected to the common supply flow path 80b and a plurality of individual recovery flow paths 1009 connected to the common recovery flow path 80c are formed for each ejection port 1006. FIG.

With the above-described configuration, in the recording element substrate 80a, the liquid flows in from the common supply channel 80b with relatively weak negative pressure (high absolute pressure value), and relatively strong negative pressure (low absolute pressure value). A flow of ink is generated that flows out to the common recovery channel 80c. More specifically, the ink flows in the order of common supply channel 80b→individual supply channel 1008→pressure chamber 1005→individual recovery channel 1009→common recovery channel 80c. When the ink is ejected by the printing elements 1004, part of the ink that moves from the common supply channel 80b to the common recovery channel 80c is ejected from the ejection port 1006 and discharged to the outside of the print head 8. FIG. On the other hand, the ink not ejected from the ejection port 1006 is recovered to the recovery channel C4 through the common recovery channel 80c.

Based on the above configuration, when performing a printing operation, the ink supply control unit 209 closes the tank supply valve V1 and the head replacement valve V5, opens the air release valve V0, the supply valve V2, and the recovery valve V4, and supplies Drive pump P1 and recovery pump P2. As a result, a circulation path of sub-tank 151→supply channel C2→recording head 8→recovery channel C4→sub-tank 151 is established. When the amount of ink supplied from the supply pump P1 per unit time is larger than the total value of the discharge amount per unit time of the recording head 8 and the flow rate per unit time of the recovery pump P2, the supply flow path C2 to the relief flow path Ink flows into C3. As a result, the flow rate of ink flowing into the recording head 8 from the supply channel C2 is adjusted.

When the printing operation is not performed, the ink supply control unit 209 stops the supply pump P1 and the recovery pump P2, and closes the atmosphere open valve V0, the supply valve V2, and the recovery valve V4. As a result, the flow of ink in the printhead 8 is stopped, and backflow due to the difference in water head between the sub-tank 151 and the printhead 8 is also suppressed. In addition, by closing the air release valve V0, leakage of ink from the sub-tank 151 and evaporation of ink are suppressed.

<Description of thickened ink>
FIG. 7 is a diagram for explaining how thickened ink is generated. FIG. 7 is a diagram showing a cross section around the ejection port 1006, like FIG. 6B. Note that the top and bottom of FIG. 6B are reversed. FIG. 7A is a diagram illustrating a case in which short-time circulation is repeated as a comparative example. FIG. 7B is a diagram for explaining an outline of processing in this embodiment. In FIG. 7, it is assumed that the time axis moves from left to right in the figure.

First, a description will be given using a comparative example shown in FIG. As described above, in the present embodiment, ink circulation starts when a printing operation is performed. Then, when the recording operation ends, the circulation of ink stops. A state 700 indicates a normal state in which the ink is not thickened. A state 701 indicates a standby state in which no printing operation is being performed, that is, ink circulation is stopped. In state 701, the ink inside the ejection port 1006 gradually thickens from the portion that contacts the air. This is because the volatile components in the ink inside the ejection port 1006 evaporate into the air, and the characteristics of the ink near the ejection port 1006 change.

After that, when the recording operation is performed, the ink starts to circulate. When the ink is circulated, the ink also flows near the pressure chamber 1005 and the ejection port 1006 . Due to this flow of ink, the ink whose viscosity is beginning to increase in the vicinity of the ejection port 1006 is diffused in the flow path, so that it is possible to prevent the thickened ink from accumulating in the vicinity of the ejection port 1006 .

Here, when the printing operation is finished in a short time, the ink circulation operation is also finished in a short time according to the printing time. A state 702 is a state near the discharge port 1006 when a short-time circulation operation is performed. As shown in state 702, when the circulation operation is performed for a short period of time, the thickening of the ink in the vicinity of the ejection port 1006 cannot be sufficiently eliminated.

A state 710 indicates a state near the ejection port 1006 after such short-time circulation operations have been repeatedly performed. The thickened ink accumulates in the vicinity of the ejection port 1006 and then adheres to the ejection port 1006 . A state 711 shows a state in which, even if ink is to be ejected in a printing operation in such a state that the ink is fixed, it cannot be ejected normally.

FIG. 7B shows the vicinity of the ejection port 1006 when the process according to this embodiment is performed. A state 750, like the state 700, indicates a normal state in which the ink is not thickened. State 751, like state 701, indicates a standby state in which ink circulation is stopped. In state 751, as in state 701, the ink inside the ejection port 1006 begins to thicken.

State 752, like state 702, indicates a case where the recording operation ends in a short period of time. However, in this embodiment, when the printing operation ends in a short period of time, in addition to the original circulation time (time for circulation corresponding to the printing operation), processing is performed to continue the circulation operation for a predetermined time. Therefore, as shown in state 752, the thickened ink near the ejection port 1006 diffuses into the flow path, and the thickening of the ink near the ejection port 1006 is eliminated.

A state 760 indicates a state near the discharge port 1006 after a short-time circulation operation followed by a predetermined time continuous circulation operation is repeatedly performed. In state 761 , thickened ink is not accumulated near the ejection port 1006 . Therefore, ink is normally ejected from the ejection port 1006 when the printing operation is performed in the state 761 . In this embodiment, it is assumed that each color ink is continuously circulated for a predetermined time.

<Flowchart>
FIG. 8 is a diagram showing a flowchart when a recording operation is performed in this embodiment. A series of processing shown in the flowchart of FIG. 8 is performed by the print controller 202 developing the program code stored in the ROM 203 in the RAM 204 and executing the program code. Alternatively, some or all of the functions of the steps in FIG. 8 may be realized by hardware such as an ASIC or an electronic circuit. Note that the symbol "S" in the description of each process means a step in the flowchart.

FIG. 8(a) is a flowchart showing the overall processing. In S810, the print controller 202 acquires a print instruction. For example, the print controller 202 acquires a recording instruction by receiving a recording instruction corresponding to a print job from the main controller 101 .

In S820, the print controller 202 controls the ink supply control unit 209 to start circulation of ink. The print controller 202 also stores the ink circulation start time Ts in the RAM 204 .

In S830, the print controller 202 controls the image processing controller 205, the transport control unit 207, and the head carriage control unit 208 to perform a printing operation. For example, if the print job includes an instruction to print on 10 sheets of recording medium, the operation of printing on 10 sheets of recording medium is performed in S830. If the print job includes instructions for printing on five recording media, a printing operation on five recording media is performed in S830. If the recording operation has ended, the process proceeds to S840.

At S840, print controller 202 performs an additional cycle sequence. The additional circulation sequence is a process of additionally circulating when the circulation time is short. As described above, the ink circulation operation continues while the printing operation is being performed in S830. The circulation time of the ink can change according to the time of the printing operation. Also, the time required for the recording operation may change according to the print job input by the user. In other words, the printing apparatus 1 side cannot uniformly determine the circulation time corresponding to the printing operation. For this reason, in the present embodiment, as will be described later, processing for additionally continuing the circulation is performed according to the circulation time.

FIG. 8(b) is a flowchart for explaining the details of the additional circulation sequence of S840. In S841, the print controller 202 acquires the elapsed time Tc from the circulation start time Ts in S820. The elapsed time Tc indicates the elapsed time of circulation performed in one recording operation (recording operation performed according to one print job). That is, the elapsed time Tc is the time corresponding to the recording operation time in S830. The print controller 202 determines whether the elapsed time Tc from the circulation start time Ts is less than the specified value Tmin. If it is less than the specified value Tmin, the process proceeds to S842. If it is equal to or greater than the specified value Tmin, S842 is skipped and the process proceeds to S843.

In S842, the print controller 202 continues the circulation for the time Tadd. The specified value Tmin and the value of Tadd, which is the time to continue circulation (also referred to as additional circulation time), can be set as appropriate. As an example, the specified value Tmin can be set to 5 seconds, and the additional circulation time Tadd can be set to 4 seconds. By the processing of S842, when the recording operation is for a short time less than the specified value Tmin, the circulation is continued for the time Tadd. Therefore, it is possible to eliminate the thickening of the ink in the vicinity of the ejection port 1006 as shown in the state 752 of FIG. 7B. After that, the process proceeds to S843.

In S843, the print controller 202 stops ink circulation. Then, the process ends. When the elapsed time Tc from the circulation start time Ts is equal to or greater than the specified value Tmin, it is estimated that the thickening of the ink in the vicinity of the ejection port 1006 has been sufficiently eliminated, and therefore no additional continuous circulation operation is performed. .

As described above, in the present embodiment, the circulation time is continued when one circulation time during the printing operation is less than the predetermined time. As a result, it is possible to suppress the accumulation of thickened ink and prevent the ink from sticking and being unable to be ejected normally.

<Modification>
Note that in the first embodiment, an example has been described in which the processing of the additional circulation sequence shown in FIG. 8 is performed for each color of ink, but the present invention is not limited to this. Additional circulation sequences may be processed only for specific inks. For example, it is known that ink containing a large amount of pigment tends to thicken. Black ink, for example, is used as the ink containing a large amount of pigment. In this case, only black ink may be subject to the additional circulation sequence of S840.

As an example, assume that the recording apparatus 1 has a mode in which only black ink is circulated and a mode in which all colors including black ink are circulated. The mode of circulating only black ink is selected when the print instruction acquired in S810 of FIG. 8A is an instruction based on a monochrome print job. The mode of circulating all colors including black ink is selected when the print instruction acquired in S810 is an instruction based on a color print job. When the print controller 202 operates in a mode in which only black ink is circulated, the circulation time may be continued for the time Tadd in S842 of FIG. 8B. If the print controller 202 is operating in a mode that circulates all colors including black ink, in S842, it is sufficient to switch to a mode that circulates only black ink and continue the circulation time for the time Tadd.

Alternatively, a form in which circulation control is performed individually for each color may be employed. In such a form, when ink of a color containing at least black ink is being circulated, only the black ink may continue to circulate in S842.

As an example of continuing the circulation time only for a specific ink, the ink that tends to thicken has been taken as an example, but the present invention is not limited to this. For example, the circulation time of ink ejected using an ejection port whose characteristics such as the shape of the ejection port tend to thicken more than other ink ejection ports may be continued.

It is also assumed that the next recording instruction is acquired while the circulation time is continuing. In such a case, the additional circulation sequence of S840 can be terminated and the processing can be performed again from the processing of S810. In this case, in S820, the previous circulation start time Ts may be used continuously without being cleared.

<<Embodiment 2>>
In the first embodiment, an example has been described in which the specified value Tmin and the additional circulation time Tadd are predetermined fixed values. In this embodiment, an example will be described in which the specified value Tmin and the additional circulation time Tadd are variable values according to the installation environment of the recording apparatus 1 .

The printing apparatus 1 in this embodiment is configured to be able to acquire at least one of temperature and humidity in the environment in which the printing apparatus 1 is set. For example, the printing apparatus 1 includes a thermometer and a hygrometer, and the print controller 202 acquires the temperature and humidity detected by the thermometer and hygrometer. Alternatively, the recording device 1 may be configured to be able to acquire temperature and humidity information from another device. Also, the temperature and humidity may not be measured values, and values estimated by a predetermined method may be used.

FIG. 9 is a diagram showing an example of table information referred to by the print controller 202 in this embodiment. FIG. 9(a) is table information regarding the specified value Tmin, and FIG. 9(b) is table information regarding the additional circulation time Tadd. The print controller 202 acquires at least one of the temperature and humidity, and sets the specified value Tmin and the additional circulation time Tadd to the values specified in the item corresponding to the acquired temperature and humidity. For example, when the temperature is 20° C. and the humidity is 65%, the specified value Tmin is set to 3 seconds and the additional circulation time is set to 3 seconds. When the temperature is 36 degrees and the humidity is 25%, the specified value Tmin is set to 7 seconds and the additional circulation time is set to 5 seconds. It should be noted that the setting of the specified value Tmin and the value of the additional circulation time Tadd according to the temperature and humidity can be appropriately performed at a predetermined timing. For example, the print controller 202 may change the setting value each time the additional circulation sequence of S840 in FIG. May be set.

It should be noted that the higher the temperature or the lower the humidity, the more likely the ink is to thicken. Therefore, as shown in FIG. 9, it is preferable to set both the specified value Tmin and the additional circulation time Tadd to be longer as the temperature is higher or as the humidity is lower.

By setting the specified value Tmin and the additional circulation time Tadd to variable values using the information about the installation environment of the printing apparatus 1 in this way, it is possible to more appropriately suppress the thickening of the ink. In addition, power consumption can be suppressed by preventing circulation more than necessary.

<<Embodiment 3>>
In Embodiment 1 and Embodiment 2, when the circulation time per cycle is less than the predetermined time, the circulation time is continued. That is, in the case where the short-time circulation is repeated in which the circulation time per cycle is less than the predetermined time, the mode in which the circulation time is continued in each circulation has been described. In this embodiment, the number of repetitions of short-time circulation is counted, and when the count value reaches a predetermined value, the circulation time is continued. Note that in the present embodiment, it is expected that the ink will thicken to some extent, so it is preferable to set the additional circulation time to be longer than the time described in the first embodiment.

FIG. 10 is a flowchart for explaining the additional circulation sequence in this embodiment. FIG. 10 is a diagram showing detailed processing in S840 of FIG. 8(a).

In S1001, the print controller 202 acquires the elapsed time Tc from the circulation start time Ts. As in the first embodiment, the elapsed time Tc indicates the duration of circulation performed in one recording operation (recording operation performed according to one print job). The print controller 202 determines whether the elapsed time Tc from the circulation start time Ts is less than the specified value Tmin2. If it is less than the specified value Tmin2, the process proceeds to S1002. If it is equal to or greater than the specified value Tmin2, S1002 is skipped and the process proceeds to S1003. The specified value Tmin2 is, for example, 5 seconds.

In S1002, the print controller 202 adds 1 to the count value N indicating the number of times of short-time printing. Then, the process proceeds to S1003. That is, in the present embodiment, even if the elapsed time Tc from the circulation start time Ts is less than the specified value Tmin2, circulation is not continued immediately.

In S1003, the print controller 202 determines whether the count value N is greater than or equal to a predetermined value Nth. The predetermined value Nth is, for example, 10 times. If the count value N is greater than or equal to the predetermined value Nth, the process proceeds to S1004. If the count value N is not equal to or greater than the predetermined value Nth, S1004 is skipped and the process proceeds to S1005.

In S1004, the print controller 202 continues circulation for Tadd2 minutes. The additional circulation time Tadd2 is, for example, 25 seconds. After that, the process proceeds to S1005.

In S1005, the print controller 202 stops ink circulation. According to the processing described above, even when short-time circulation is repeated in which the circulation time per cycle is less than the predetermined time, additional circulation is performed when the number of short-time circulations reaches the predetermined number of times. The circulation is continued for the time Tadd2 minutes. Therefore, thickening of the ink can be suppressed.

As described above, the circulation time associated with the recording operation can change according to the recording instruction, and short-time circulation is not necessarily repeated. For example, a long cycle may be performed after several short cycle cycles. In such a case, the thickening of the ink is eliminated by the long circulation operation. Therefore, for example, the print controller 202 may perform control to update or reset the count value to a value smaller than the current value when the circulation operation is performed for the second time or more. The second time may be, for example, specified value Tmin2+additional circulation time Tadd2.

Further, when a cleaning operation (for example, preliminary ejection), which has a greater effect of eliminating the thickening of the ink near the ejection port 1006 than the circulation operation, is performed, the print controller 202 performs control to reset the count value. you can go

<Modification>
In the flowchart of FIG. 10, in the process of S1002, the value to be added to the count value N has been described as a fixed value "1", but the present invention is not limited to this. A value for updating the count value N may be a negative value, or may be a variable value instead of a fixed value. The count value N may be updated by addition or subtraction with a value weighted according to the elapsed time Tc from the circulation start time Ts (that is, the circulation time associated with the printing operation). For example, the shorter the elapsed time Tc (circulation time), the larger the count value N may be added, and the longer the elapsed time Tc (circulation time), the larger the count value N may be subtracted.

Also, as described in the second embodiment, the value to be added or subtracted from the count value may be changed according to the temperature and humidity. FIG. 11 is a diagram showing an example of table information used in this embodiment. FIG. 11 shows an example of addition/subtraction values according to elapsed time Tc (circulation time) and temperature. As shown in FIG. 11, when the elapsed time Tc is long, the added value is smaller or the subtracted value is larger than when the elapsed time Tc is short. In a modification, the print controller 202 may replace the process of S1002 with a process of updating the count value N using the value obtained by referring to the table information in FIG. When the count value becomes negative, it is set to "0" and treated as being substantially reset. FIG. 11 shows an example of addition/subtraction values corresponding to the elapsed time Tc (circulation time) and temperature. may be used.

<<Embodiment 4>>
In the present embodiment, the operation of capping the printhead 8 by the cap unit 10 after the end of the printing operation requires a predetermined time or longer. As described above, the recording apparatus 1 is in a state in which the cap unit 10 abuts against the discharge port surface 8a of the recording head 8 to protect the discharge port surface 8a during standby. Then, when recording is started, the cap unit 10 is separated from the ejection port surface 8a (called cap open), and ink is ejected from the ejection port surface 8a. When the recording is completed, the cap unit 10 abuts against the ejection port surface 8a to cap the ejection port surface 8a (referred to as cap closing).

In the present embodiment, it is assumed that the operation of closing the cap takes, for example, 5 seconds. That is, it is assumed that the cap closing operation requires a time corresponding to the additional circulation time Tadd described in the first embodiment. Further, in the present embodiment, once the cap closing operation is started, it is assumed that the cap is closed without interruption. In such a case, once the cap closing operation is started, the recording operation cannot be started (that is, the cap cannot be opened) for a predetermined time until the cap closing operation is completed. Therefore, by continuing the circulation time according to the predetermined time required for the cap closing operation, it is possible to suppress the thickening of the ink without generating additional time accompanying the continuation of the circulation.

FIG. 12 is a diagram showing a flowchart of this embodiment. In S1210, the print controller 202 acquires a print instruction. In S1220, the print controller 202 performs cap open operation. Also, at S1230, the print controller 202 starts ink circulation. S1220 and S1230 are processed in parallel.

At S<b>1240 , the print controller 202 starts adjusting the temperature of the print head 8 . The printing element substrate 80a of this embodiment is provided with a sub-heater (not shown) in addition to the printing elements 1004 . Then, the temperature of the ink in the print head 8 is adjusted by heating the print head 8 or the ink in the print head 8 with a sub-heater so that the ink is stably ejected from the ejection port 1006 during printing. processing takes place.

In S1250, the print controller 202 performs a printing operation. When the recording operation is completed, the print controller 202 stops adjusting the temperature of the recording head 8 in S1260. Note that if the temperature of the print head 8 is adjusted while the circulation is stopped, the evaporation of water from the ejection port 1006 will be accelerated, and the thickening of the ink will be accelerated. Therefore, in the case of the configuration in which the temperature of the print head 8 is adjusted, the temperature adjustment of the print head 8 is stopped prior to the subsequent additional circulation sequence.

Following the processing of S1260, the print controller 202 performs a cap closing operation in S1270. Further, following the processing of S1260, in parallel with S1270, the print controller 202 performs an additional circulation sequence.

In the additional circulation sequence of S1270, for example, the same processing as the processing described with reference to FIG. 8B is performed. In this embodiment, it is assumed that the specified value Tmin is set to a very large value, eg, 9999 seconds, and the additional circulation time Tadd is set to 5 seconds. That is, as a result of the determination in S841, the process proceeds to S842. The additional circulation time Tadd corresponds to the time required for the cap closing operation. Alternatively, the additional circulation time Tadd may be less than the time required for the cap closing operation.

According to such processing and setting, the circulation time is continued corresponding to the cap closing operation time. For this reason, thickening of the ink can be suppressed without generating additional time associated with the continuation of circulation. In addition, it is possible to suppress the accumulation of slight thickening that occurs during the cap closing operation.

In the present embodiment, the specified value Tmin is set to a very large value. good. Such a configuration is particularly effective when using ink that tends to be not normally ejected while circulation is stopped, or when it takes time to close the cap.

In the present embodiment, an example of performing both the cap opening operation, the cap closing operation, and the temperature adjustment of the print head 8 has been described. may

<<other embodiments>>
You may employ|adopt the form which combined each embodiment demonstrated above with another embodiment or modification. For example, the processing of the flowchart of FIG. 10 described in the third embodiment may be performed only for specific inks. Further, the processing described in the first embodiment may be performed for a specific ink, and the processing described in the third embodiment may be performed for other inks, or vice versa. Further, the additional circulation sequence described in the fourth embodiment may be performed only for specific inks, and the processing described in the first to third embodiments may be performed for other inks.

8 recording head 202 print controller 1006 ejection port 1005 pressure chamber

Claims (26)

an ejection port for ejecting ink supplied from a tank containing ink ; an energy generating element provided corresponding to the ejection port for generating energy used for ejecting the liquid; a pressure chamber located opposite to the energy generating element and communicating with the ejection port and filled with the ink to be ejected from the ejection port, and performing a recording operation by ejecting ink from the ejection port a head ;
circulation means for circulating ink in a circulation path including the pressure chamber when the recording operation is performed, and for stopping circulation of the ink when the recording operation is finished;
adjusting means for adjusting the temperature of the recording head;
a control means for controlling to stop the circulation after the circulation means continues the circulation for a predetermined time after the recording operation is completed ;
The inkjet recording apparatus, wherein the control means starts adjusting the temperature when the recording operation is performed, and performs the control after stopping the adjustment of the temperature when the recording operation is finished. . 3. The control means causes the circulation means to continue the circulation for the predetermined time when the elapsed time of the circulation from the start of the circulation performed according to the recording operation is less than a specified value. 1. The inkjet recording apparatus according to 1. 3. An inkjet recording apparatus according to claim 2, wherein said prescribed value and said predetermined time are set according to an environment in which said inkjet recording apparatus is installed. The control means is
At least one of the temperature and humidity of the environment in which the inkjet recording device is installed can be obtained,
4. An ink jet recording apparatus according to claim 3, wherein said specified value and said predetermined time are set based on at least one of said temperature and humidity. The control means sets at least one of the specified value and the predetermined time to be longer at a second temperature higher than the first temperature than at the first temperature, and 5. The inkjet according to claim 4, wherein the second humidity lower than the humidity is set so that at least one of the specified value and the predetermined time is longer than in the case of the first humidity. recording device. an ejection port for ejecting ink supplied from a tank containing ink ; an energy generating element provided corresponding to the ejection port for generating energy used for ejecting the liquid; a pressure chamber located opposite to the energy generating element and communicating with the ejection port and filled with the ink to be ejected from the ejection port, and performing a recording operation by ejecting ink from the ejection port a head ;
circulation means for circulating ink in a circulation path including the pressure chamber when the recording operation is performed, and for stopping circulation of the ink when the recording operation is finished;
An inkjet recording device comprising
updating the count value with a first value if the elapsed time of circulation from the start of circulation performed in response to the recording operation is less than a specified value when the recording operation is completed;
1. An inkjet recording apparatus, comprising: control means for controlling said circulation means to continue circulation for a predetermined time and then stop said circulation when the updated count value reaches a predetermined value. 7. An inkjet recording apparatus according to claim 6, wherein said first value changes according to said elapsed time. 8. An inkjet recording apparatus according to claim 6, wherein said first value varies according to the environment in which said inkjet recording apparatus is installed. The control means is
9. The inkjet recording apparatus according to any one of claims 6 to 8, wherein when the elapsed time satisfies the specified value, the count value is not added or the count value is subtracted. 6. The control means resets the count value when the elapsed time is longer than the sum of the specified value and the predetermined time, or when a predetermined maintenance operation has been performed. 10. The inkjet recording apparatus according to any one of 9. further comprising a cap unit that protects the ejection port by coming into contact with the recording head;
the control means is configured to move the cap unit away from the recording head when the recording operation is performed, and to bring the cap unit into contact with the recording head when the recording operation is completed;
6. The ink jet recording apparatus according to claim 2, wherein the control means performs the control using a value corresponding to the moving time of the cap unit as the specified value. further comprising adjusting means for adjusting the temperature of the recording head;
6. The control means starts the adjustment of the temperature when the recording operation is performed, and performs the control after stopping the adjustment of the temperature when the recording operation ends. 11. The inkjet recording apparatus according to any one of 10 to 10 . a supply channel for supplying the ink from the tank to the recording head;
a recovery channel for recovering the ink from the recording head to the tank;
13. The circulation device according to any one of claims 1 to 12, wherein when the recording operation is performed, the circulation means circulates the ink through the circulation path including the supply channel, the inside of the pressure chamber, and the recovery channel. 1. The inkjet recording apparatus according to claim 1. The tank, the supply channel and the recovery channel are provided for each color of ink,
14. An inkjet recording apparatus according to claim 13, wherein said control means performs said control when a specific ink is circulated. 15. An inkjet recording apparatus according to claim 14 , wherein said specific ink is black ink. an ejection port for ejecting ink supplied from a tank containing ink ; an energy generating element provided corresponding to the ejection port for generating energy used for ejecting the liquid; a pressure chamber located opposite to the energy generating element and communicating with the ejection port and filled with the ink to be ejected from the ejection port, and performing a recording operation by ejecting ink from the ejection port a head ;
circulation means for circulating ink in a circulation path including the pressure chamber when the recording operation is performed, and for stopping circulation of the ink when the recording operation is finished;
a cap unit that protects the ejection port by coming into contact with the recording head;
control means for separating the cap unit from the recording head when the recording operation is performed and bringing the cap unit into contact with the recording head when the recording operation is completed;
An inkjet recording device comprising
The control means causes the circulation means to continue circulation for a predetermined time while the cap unit is brought into contact with the recording head in response to the completion of the recording operation, and then stops the circulation. An ink jet recording apparatus characterized by controlling to cause When the time required for the operation of bringing the cap unit into contact with the recording head in response to the termination of the recording operation is less than a predetermined time, the control means controls the capping operation in response to the termination of the recording operation. 17. An ink jet recording apparatus according to claim 16 , wherein the circulation means is kept circulating while the unit is brought into contact with the recording head, and then the circulation is stopped. a supply channel for supplying the ink from the tank to the recording head;
a recovery channel for recovering the ink from the recording head to the tank;
18. The method according to claim 16, wherein the circulation means circulates the ink through the circulation path including the supply channel, the inside of the pressure chamber, and the recovery channel when the recording operation is performed. Inkjet recording device. an ejection port for ejecting ink supplied from a tank containing ink; an energy generating element provided corresponding to the ejection port for generating energy used for ejecting the liquid; and the energy generation a print head that is located opposite to the element, has a pressure chamber that communicates with the ejection port and is filled with the ink ejected from the ejection port, and performs a printing operation by ejecting ink from the ejection port;
circulation means for circulating ink in a circulation path including the pressure chamber when the recording operation is performed, and for stopping circulation of the ink when the recording operation is finished;
a control means for controlling to stop the circulation after the circulation means continues the circulation for a predetermined time after the recording operation is completed;
Ink jet recording, wherein the control means causes the circulation means to continue the circulation for the predetermined time when the elapsed time of circulation from the start of circulation performed in accordance with the recording operation is less than a specified value. Device. an ejection port for ejecting ink supplied from a tank containing ink; an energy generating element provided corresponding to the ejection port for generating energy used for ejecting the liquid; and the energy generation a print head that is located opposite to the element, has a pressure chamber that communicates with the ejection port and is filled with the ink ejected from the ejection port, and performs a printing operation by ejecting ink from the ejection port;
a supply channel for supplying the ink from the tank to the recording head;
a recovery channel for recovering the ink from the recording head to the tank;
circulating means for circulating ink in a circulation path including the supply channel, the inside of the pressure chamber, and the recovery channel when the recording operation is performed, and stopping circulation of the ink when the recording operation is finished; ,
a control means for controlling to stop the circulation after the circulation means continues the circulation for a predetermined time after the recording operation is completed;
The tank, the supply channel and the recovery channel are provided for each color of ink,
The inkjet recording apparatus, wherein the control means performs the control when a specific ink is circulated. 21. An inkjet recording apparatus according to claim 20, wherein said specific ink is black ink. an ejection port for ejecting ink supplied from a tank containing ink; an energy generating element provided corresponding to the ejection port for generating energy used for ejecting the liquid; a pressure chamber located opposite to the energy generating element and communicating with the ejection port and filled with the ink to be ejected from the ejection port, and performing a recording operation by ejecting ink from the ejection port a head ;
circulation means for circulating ink in a circulation path including the pressure chamber when the recording operation is performed, and for stopping circulation of the ink when the recording operation is finished;
A control method for an inkjet recording apparatus comprising
When the recording operation is finished, if the elapsed time of circulation from the start of circulation performed according to the recording operation is less than a specified value, the circulation is continued for a predetermined time by the circulation means, and then the circulation is stopped. A control method for an inkjet recording apparatus, comprising: an ejection port for ejecting ink supplied from a tank containing ink ; an energy generating element provided corresponding to the ejection port for generating energy used for ejecting the liquid; a pressure chamber located opposite to the energy generating element and communicating with the ejection port and filled with the ink to be ejected from the ejection port, and performing a recording operation by ejecting ink from the ejection port a head ;
circulation means for circulating ink in a circulation path including the pressure chamber when the recording operation is performed, and for stopping circulation of the ink when the recording operation is finished;
A control method for an inkjet recording apparatus comprising
updating the count value with a first value when the elapsed time of the circulation from the start of the circulation performed in response to the recording operation is less than a specified value when the recording operation is completed;
when the updated count value reaches a predetermined value, causing the circulation means to continue the circulation for a predetermined time, and then stopping the circulation;
A control method for an inkjet recording apparatus, comprising: an ejection port for ejecting ink supplied from a tank containing ink ; an energy generating element provided corresponding to the ejection port for generating energy used for ejecting the liquid; and the energy a pressure chamber located opposite to the generating element and communicating with the ejection port and filled with the ink to be ejected from the ejection port, the print head performing a printing operation by ejecting ink from the ejection port and
circulation means for circulating ink in a circulation path including the pressure chamber when the recording operation is performed, and for stopping circulation of the ink when the recording operation is finished;
a cap unit that protects the ejection port by coming into contact with the recording head;
control means for separating the cap unit from the recording head when the recording operation is performed and bringing the cap unit into contact with the recording head when the recording operation is completed;
A control method for an inkjet recording apparatus comprising
The control means causes the circulation means to continue circulation for a predetermined time while the cap unit is brought into contact with the recording head in response to the completion of the recording operation, and then stops the circulation. A control method for an inkjet recording apparatus, comprising: When the time required for the operation of bringing the cap unit into contact with the recording head in response to the termination of the recording operation is less than a predetermined time, the control means controls the capping operation in response to the termination of the recording operation. 25. Control of an ink jet recording apparatus according to claim 24, further comprising a step of causing said circulation means to continue circulation while performing an operation of bringing said unit into contact with said recording head, and then stopping said circulation. Method. Inkjet recording equipment
a supply channel for supplying the ink from the tank to the recording head;
a recovery channel for recovering the ink from the recording head to the tank;
26. The circulation device according to any one of claims 22 to 25, wherein when the recording operation is performed, the circulation means circulates the ink through the circulation path including the supply channel, the inside of the pressure chamber, and the recovery channel. A control method for an inkjet recording apparatus according to claim 1.

Images