JP6921618B2 - Recording device, recording device control method, and program - Google Patents

Description

The present invention relates to a recording device, a method for controlling the recording device, and a program.

Patent Document 1 discloses that ink is collected when the recording head is replaced, and the recovered ink is reused after the recording head is replaced.

U.S. Pat. No. 8,733,908

However, in Patent Document 1, air taken in from the outside is used as the air sent to the flow path when collecting the ink, and there is a risk of promoting the evaporation of the ink when the taken-in air is dry. ..

Therefore, in view of the above problems, it is an object of the present invention to suppress evaporation of the liquid when the liquid in the circulation system is collected in the tank in a recording device having a circulation system in which the liquid circulates.

In the present invention, a tank for accommodating a liquid, a recording head for discharging the liquid, a first flow path connected to the liquid layer in the tank, and a second flow path connected to the air layer in the tank. A third flow path that connects the flow path, the confluence of the first flow path and the second flow path, and the recording head, and a fourth flow path that connects the recording head and the tank. A circulation means provided in the third flow path for circulating the liquid or air in a circulation path including the tank and the recording head, and either the first flow path or the second flow path. It is a recording device including a switching means for making one of them usable.

According to the present invention, in a recording device having a circulation system in which a liquid circulates, it is possible to suppress evaporation of the liquid when the liquid in the circulation system is collected in a tank.

It is a figure when the recording device is in a standby state. It is a block diagram which shows the control composition of a recording apparatus. It is a figure when the recording apparatus is in a recording state. (A) to (c) are transport route diagrams of the recording medium supplied from the first cassette. (A) to (c) are transport route diagrams of the recording medium supplied from the second cassette. (A) to (d) are transport route diagrams when a recording operation is performed on the back surface of the recording medium. It is a figure when the recording device is in a maintenance state. (A) and (b) are perspective views which show the structure of the maintenance unit. (A) and (b) are diagrams showing a circulation type ink supply system. (A) and (b) are diagrams showing the operation of the circulation type ink supply system. It is a flowchart of an ink filling process. (A) to (e) are diagrams showing each state in the ink filling process. It is a flowchart of the process executed in the ink recovery mode. (A) and (b) are diagrams showing each state in the ink recovery mode.

Hereinafter, the liquid discharge head and the liquid discharge device according to the embodiment of the present invention will be described with reference to the drawings. In the following embodiments, the inkjet recording head and the inkjet recording apparatus for ejecting ink will be described with a specific configuration, but the present invention is not limited thereto. The liquid discharge head, the liquid discharge device, and the liquid supply method of the present invention are industrially combined with devices such as a printer, a copying machine, a facsimile having a communication system, a word processor having a printer unit, and various processing devices. Applicable to recording equipment. For example, it can also be used for biochip fabrication and electronic circuit printing. Further, since the embodiments described below are appropriate specific examples of the present invention, various technically preferable limitations are added. However, the embodiments are not limited to the embodiments and other specific methods described below as long as they are in line with the idea of the present invention.

<About the internal configuration of the recording device>
FIG. 1 is an internal configuration diagram of an inkjet recording device 1 (hereinafter, recording device 1) used in the present embodiment. In the figure, the x direction indicates the horizontal direction, the y direction (the direction perpendicular to the paper surface) indicates the direction in which the discharge ports are arranged in the recording head 8 described later, and the z direction indicates the vertical direction.

The recording device 1 is a multifunction device including a printing unit 2 and a scanner unit 3, and various processing related to a recording operation and a reading operation can be executed individually or in conjunction with the printing unit 2 and the scanner unit 3. The scanner unit 3 includes an ADF (auto document feeder) and an FBS (flatbed scanner), and reads a document automatically fed by the ADF and a document placed on the FBS document stand by the user (scanning). )It can be performed. Although the present embodiment is a multifunction device having both the printing unit 2 and the scanner unit 3, the embodiment may not include the scanner unit 3. FIG. 1 shows a state in which the recording device 1 is in a standby state in which neither a recording operation nor a reading operation is performed.

In the print section 2, a first cassette 5A and a second cassette 5B for accommodating the recording medium (cut sheet) S are detachably installed on the bottom of the housing 4 below in the vertical direction. The first cassette 5A contains a relatively small recording medium up to A4 size, and the second cassette 5B contains a relatively large recording medium 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 in the vicinity of the second cassette 5B. When the recording operation is performed, the recording medium S is selectively fed from one of the cassettes.

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

The guide 18 is provided in the transport path of the recording medium S and guides the recording medium S in a predetermined direction. The inner guide 19 has a curved side surface with a member extending in the y direction, 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 discharge tray 13 is a tray for loading and holding the recording medium S discharged by the discharge roller 12 after the recording operation is completed.

The recording head 8 of the present embodiment is a full-line type color inkjet recording head, and has a plurality of ejection ports for ejecting ink according to the recording data as much as the width of the recording medium S along the y direction in FIG. It is arranged. When the recording head 8 is in the standby position, the discharge 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 the recording operation, the print controller 202, which will be described later, changes the orientation of the recording head 8 so that the discharge port surface 8a 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 surface. The movement of the recording head 8 from the standby position to the recording position will be described in detail later.

The ink tank unit 14 stores four colors of ink 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 the flow rate of the ink in the recording head 8 within an appropriate range. In this embodiment, a circulation type ink supply system is adopted, 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 collected from the recording head 8 within an appropriate range.

The maintenance unit 16 includes a cap unit 10 and a wiping unit 17, and operates them at a predetermined timing to perform a maintenance operation on the recording head 8. The maintenance operation will be described in detail later.

<Regarding the control configuration of the recording device>
FIG. 2 is a block diagram showing a control configuration in the recording device 1. The control configuration is mainly composed of a print engine unit 200 that controls the print unit 2, a scanner engine unit 300 that controls the scanner unit 3, and a controller unit 100 that controls the entire recording device 1. The print controller 202 controls various mechanisms of the print engine unit 200 according to the instructions of 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. The details of the control configuration will be described below.

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

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

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

In the print engine unit 200, the print controller 202 configured by the CPU controls various mechanisms included in the print unit 2 while using the RAM 204 as a work area according to the programs and various parameters stored in the 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 the recording data so that the recording head 8 can be used for the recording operation. When the recorded data is generated, the print controller 202 causes the recording head 8 to execute a recording operation based on the recorded data via the head I / F 206. At this time, the print controller 202 drives the feeding units 6A and 6B, the transport roller 7, the discharge roller 12, and the flapper 11 shown in FIG. 1 via the transport control unit 207 to transport the recording medium S. According to the instruction of 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 the printing process is performed.

The head carriage control unit 208 changes the direction and position of the recording head 8 according to an operating state such as a maintenance state or a recording state of the recording device 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 falls within an appropriate range. The maintenance control unit 210 controls the operations of the cap unit 10 and the wiping unit 17 in the maintenance unit 16 when performing the maintenance operation on the recording head 8.

In the scanner engine unit 300, the main controller 101 controls the hardware resources of the scanner controller 302 while using the RAM 106 as a work area according to the programs and various parameters stored in the ROM 107. As a result, various mechanisms included in the scanner unit 3 are controlled. For example, when the main controller 101 controls the hardware resources in the scanner controller 302 via the controller I / F 301, the document loaded on the ADF by the user is conveyed via the transfer control unit 304 and read by the sensor 305. .. Then, the scanner controller 302 saves the read image data in the RAM 303. The print controller 202 can cause the recording head 8 to execute a recording operation based on the image data read by the scanner controller 302 by converting the image data acquired as described above into the recording data. ..

<About the operation of the recording device in the recording state>
FIG. 3 shows when the recording device 1 is in the recording state. Compared with the standby state shown in FIG. 1, the cap unit 10 is separated from the discharge port surface 8a of the recording head 8, and the discharge port surface 8a faces the platen 9. In the present embodiment, the plane of the platen 9 is tilted by about 45 degrees with respect to the horizontal direction, and the discharge port surface 8a of the recording head 8 at the recording position is also in the horizontal direction so that the distance from the platen 9 is kept constant. It is tilted about 45 degrees with respect to.

When the recording head 8 is moved from the standby position shown in FIG. 1 to the recording position shown in FIG. 3, the print controller 202 uses the maintenance control unit 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. After that, the print controller 202 is rotated by 45 degrees while adjusting the height of the recording head 8 in the vertical direction by using the head carriage control unit 208, so that the discharge port surface 8a faces the platen 9. When the recording operation is completed and the recording head 8 moves from the recording position to the standby position, the print controller 202 performs the reverse process of the above.

Next, the transport path of the recording medium S in the printing unit 2 will be described. When the recording command is input, the print controller 202 first moves the recording head 8 to the recording position shown in FIG. 3 by using the maintenance control unit 210 and the head carriage control unit 208. After that, the print controller 202 uses the transport control unit 207 to drive either the first feeding unit 6A or the second feeding unit 6B according to the recording command, and feeds the recording medium S.

4 (a) to 4 (c) are diagrams showing a transport path when the A4 size recording medium S housed in the first cassette 5A is fed. The recording medium S loaded on the top of the first cassette 5A is separated from the second and subsequent recording media by the first feeding unit 6A, and while being nipated by the transport roller 7 and the pinch roller 7a, the platen 9 It is conveyed toward the recording area P between the recording head 8 and the recording head 8. FIG. 4A shows a transport state immediately before the tip of the recording medium S reaches the recording area P. The traveling direction of the recording medium S is changed from the horizontal direction (x direction) to a direction inclined by about 45 degrees with respect to the horizontal direction while being fed to the first feeding unit 6A and reaching the recording area P. NS.

In the recording area P, ink is ejected toward the recording medium S from a plurality of ejection ports provided in the recording head 8. The back surface of the recording medium S in the area to which the ink is applied is supported by the platen 9, and the distance between the ejection port surface 8a and the recording medium S is kept constant. The recording medium S after the ink is applied passes through the left side of the flapper 11 whose tip is tilted to the right while being guided by the transfer roller 7 and the spur 7b, and goes upward in the vertical direction of the recording device 1 along the guide 18. Be transported. FIG. 4B shows a state in which the tip of the recording medium S passes through the recording area P and is conveyed upward in the vertical direction. The traveling direction of the recording medium S is changed vertically upward by the transport roller 7 and the spur 7b from the position of the recording region P tilted by about 45 degrees with respect to the horizontal direction.

The recording medium S is conveyed upward in the vertical direction and then discharged to the discharge tray 13 by the discharge roller 12 and the spur 7b. FIG. 4C shows a state in which the tip of the recording medium S passes through the discharge roller 12 and is discharged to the discharge tray 13. The discharged recording medium S is held on the discharge tray 13 with the side on which the image is recorded by the recording head 8 facing down.

5 (a) to 5 (c) are diagrams showing a transport path when the A3 size recording medium S housed in the second cassette 5B is fed. The recording medium S loaded on the top of the second cassette 5B is separated from the second and subsequent recording media by the second feeding unit 6B, and while being nipated by the transport roller 7 and the pinch roller 7a, the platen 9 It is conveyed toward the recording area P between the recording head 8 and the recording head 8.

FIG. 5A shows a transport state immediately before the tip of the recording medium S reaches the recording area P. A plurality of transport rollers 7, a pinch roller 7a, and an inner guide 19 are arranged in a transport path from feeding to the second feeding unit 6B to reaching the recording area P, so that the recording medium S has an S shape. It is curved upwards and transported to platen 9.

The subsequent transport path is the same as in the case of the A4 size recording medium S shown in FIGS. 4 (b) and 4 (c). FIG. 5B shows a state in which the tip of the recording medium S passes through the recording area P and is conveyed upward in the vertical direction. FIG. 5C shows a state in which the tip of the recording medium S passes through the discharge roller 12 and is discharged to the discharge tray 13.

6 (a) to 6 (d) show a transport path when a recording operation (double-sided recording) is performed on the back surface (second surface) of the A4 size recording medium S. When double-sided recording is performed, the recording operation is performed on the second surface (back surface) after recording the first surface (front surface). Since the transfer process for recording the first surface is the same as in FIGS. 4 (a) to 4 (c), the description thereof will be omitted here. Hereinafter, the transfer process after FIG. 4C will be described.

When the recording operation on the first surface by the recording head 8 is completed and the rear end of the recording medium S passes through the flapper 11, the print controller 202 reversely rotates the transport roller 7 to record the recording medium S inside the recording device 1. Transport to. At this time, since the tip of the flapper 11 is controlled to be tilted to the left by an actuator (not shown), the tip of the recording medium S (the rear end in the recording operation of the first surface) passes through the right side of the flapper 11. It is transported downward in the vertical direction. FIG. 6A shows a state in which the front end of the recording medium S (the rear end in the recording operation of the first surface) passes through the right side of the flapper 11.

After that, the recording medium S is conveyed along the curved outer peripheral surface of the inner guide 19, and is again conveyed to the recording area P between the recording head 8 and the platen 9. At this time, the second surface of the recording medium S faces the discharge port surface 8a of the recording head 8. FIG. 6B shows a transport state immediately before the tip of the recording medium S reaches the recording area P for the recording operation on the second surface.

The subsequent transport route is the same as in the case of the first surface recording shown in FIGS. 4 (b) and 4 (c). FIG. 6C shows a state in which the tip of the recording medium S passes through the recording area P and is conveyed upward in the vertical direction. At this time, the flapper 11 is controlled by an actuator (not shown) so that the tip of the flapper 11 is tilted to the right. FIG. 6D shows a state in which the tip of the recording medium S passes through the discharge roller 12 and is discharged to the discharge tray 13.

<Maintenance operation for recording head>
Next, the maintenance operation for the recording head 8 will be described. As described with reference to FIG. 1, the maintenance unit 16 of the present embodiment includes a cap unit 10 and a wiping unit 17, and these are operated at a predetermined timing to perform a maintenance operation.

FIG. 7 is a diagram when the recording device 1 is in the maintenance state. When the recording head 8 is moved from the standby position shown in FIG. 1 to the maintenance position shown in FIG. 7, the print controller 202 moves the recording head 8 upward in the vertical direction and the cap unit 10 downward in the vertical direction. Then, the print controller 202 moves the wiping unit 17 from the retracted position to the right in FIG. 7. After that, the print controller 202 moves the recording head 8 downward in the vertical direction to a maintenance position where maintenance operation is possible.

On the other hand, when the recording head 8 is moved from the recording position shown in FIG. 3 to the maintenance position shown in FIG. 7, the print controller 202 moves the recording head 8 upward in the vertical direction while rotating the recording head 8 by 45 degrees. Then, the print controller 202 moves the wiping unit 17 to the right from the retracted position. After that, the print controller 202 moves the recording head 8 downward in the vertical direction to a maintenance position where the maintenance operation by the maintenance unit 16 is possible.

FIG. 8A is a perspective view showing a state in which the maintenance unit 16 is in the standby position, and FIG. 8B is a perspective view showing a state in which the maintenance unit 16 is in the maintenance position. 8 (a) corresponds to FIG. 1 and FIG. 8 (b) corresponds to FIG. 7. When the recording head 8 is in the standby position, the maintenance unit 16 is in the standby position shown in FIG. 8A, the cap unit 10 is moving upward in the vertical direction, and the wiping unit 17 is housed inside the maintenance unit 16. Has been done. The cap unit 10 has a box-shaped cap member 10a extending in the y direction, and by bringing this into close contact with the ejection port surface 8a of the recording head 8, evaporation of ink from the ejection port can be suppressed. Further, the cap unit 10 also has a function of collecting the ink ejected to the cap member 10a by preliminary ejection or the like and sucking the collected ink into a suction pump (not shown).

On the other hand, in the maintenance position shown in FIG. 8B, the cap unit 10 is moving downward in the vertical direction, and the wiping unit 17 is pulled out from the maintenance unit 16. The wiper unit 17 includes two wiper units, a blade wiper unit 171 and a vacuum wiper unit 172.

In the blade wiper unit 171, blade wipers 171a for wiping the discharge port surface 8a along the x direction are arranged in the y direction by a length corresponding to the arrangement region of the discharge port. When performing the wiping operation using the blade wiper unit 171, the wiping unit 17 moves the blade wiper unit 171 in the x direction in a state where the recording head 8 is positioned at a height capable of contacting the blade wiper 171a. By this movement, the ink and the like adhering to the discharge port surface 8a are wiped off by the blade wiper 171a.

At the entrance of the maintenance unit 16 when the blade wiper 171a is housed, a wet wiper cleaner 16a for removing ink adhering to the blade wiper 171a and applying a wet liquid to the blade wiper 171a is arranged. Each time the blade wiper 171a is housed in the maintenance unit 16, deposits are removed by the wet wiper cleaner 16a and a wet liquid is applied. Then, when the discharge port surface 8a is wiped next, the wet liquid is transferred to the discharge port surface 8a to improve the slipperiness between the discharge port surface 8a and the blade wiper 171a.

On the other hand, the vacuum wiper unit 172 includes a flat plate 172a having an opening extending in the y direction, a carriage 172b movable in the opening in the y direction, and a vacuum wiper 172c mounted on the carriage 172b. The vacuum wiper 172c is arranged so that the discharge port surface 8a can be wiped in the y direction as the carriage 172b moves. A suction port connected to a suction pump (not shown) is formed at the tip of the vacuum wiper 172c. Therefore, when the carriage 172b is moved in the y direction while operating the suction pump, the ink or the like adhering to the discharge port surface 8a of the recording head 8 is sucked into the suction port while being wiped by the vacuum wiper 172c. At this time, the flat plate 172a and the positioning pins 172d provided at both ends of the opening are used for aligning the discharge port surface 8a with respect to the vacuum wiper 172c.

In the present embodiment, it is possible to carry out a first wiping process in which the wiping operation by the blade wiper unit 171 is performed and the wiping operation by the vacuum wiper unit 172 is not performed, and a second wiping process in which both wiping processes are sequentially performed. .. When performing the first wiping process, the print controller 202 first pulls out the wiping unit 17 from the maintenance unit 16 in a state where the recording head 8 is retracted vertically upward from the maintenance position shown in FIG. 7. Then, the print controller 202 moves the recording head 8 vertically downward to a position where it can come into contact with the blade wiper 171a, and then moves the wiping unit 17 into the maintenance unit 16. By this movement, the ink and the like adhering to the discharge port surface 8a are wiped off by the blade wiper 171a. That is, the blade wiper 171a wipes the discharge port surface 8a when moving into the maintenance unit 16 from the position pulled out from the maintenance unit 16.

When the blade wiper unit 171 is housed, the print controller 202 then moves the cap unit 10 upward in the vertical direction to bring the cap member 10a into close contact with the discharge port surface 8a of the recording head 8. Then, the print controller 202 drives the recording head 8 in that state to perform preliminary ejection, and sucks the ink collected in the cap member 10a by the suction pump.

On the other hand, when performing the second wiping process, the print controller 202 first slides the wiping unit 17 from the maintenance unit 16 in a state where the recording head 8 is retracted vertically upward from the maintenance position shown in FIG. Pull out. Then, the print controller 202 moves the recording head 8 vertically downward to a position where it can come into contact with the blade wiper 171a, and then moves the wiping unit 17 into the maintenance unit 16. As a result, the wiping operation by the blade wiper 171a is performed on the discharge port surface 8a. Next, the print controller 202 slides the wiping unit 17 from the maintenance unit 16 and pulls it out to a predetermined position with the recording head 8 retracted vertically upward from the maintenance position shown in FIG. 7. Subsequently, the print controller 202 positions the discharge port surface 8a and the vacuum wiper unit 172 using the flat plate 172a and the positioning pin 172d while lowering the recording head 8 to the wiping position shown in FIG. 7. After that, the print controller 202 executes the wiping operation by the vacuum wiper unit 172 described above. The print controller 202 retracts the recording head 8 vertically upward, stores the wiping unit 17, and then, similarly to the first wiping process, pre-discharges the recording head 8 into the cap member and sucks the collected ink. Do the action.

<About the circulating ink supply system>
FIG. 9A is a diagram showing a circulation type ink supply system adopted in the inkjet recording apparatus 1 of the present embodiment. The circulation type ink supply system is configured by connecting an ink tank unit 14, an ink supply unit 15, and a recording head 8. Here, a circulation system for one color of ink is shown, but in reality, such a circulation system is prepared for each ink color.

The ink tank unit 14 is provided with a main tank 141 for storing a relatively large amount of ink. The ink supply unit 15 includes a buffer tank 151 and three pumps P0, P1 and P2 connected to the buffer tank 151. The circulation pumps P1 and P2 flow the ink in the entire circulation path so that the ink in the supply system moves from the circulation pump P1 to the circulation pump P2 via the buffer tank 151.

The buffer tank 151 is provided with a liquid level sensor 154. The liquid level sensor 154 is composed of two pins, and it is possible to grasp the position (height) of the ink liquid level by detecting the presence or absence of a conduction current between the two pins. That is, by using the liquid level sensor 154, it is possible to detect that the ink liquid level in the buffer tank 151 has reached the height of the liquid level sensor 154. The replenishment pump P0 operates when the remaining amount of ink in the buffer tank 151 is low, and replenishes new ink from the main tank 141. At the time of ink replenishment, the pump P0 is controlled so that the height of the ink liquid level does not exceed the height of the liquid level sensor 154. That is, when the ink liquid level in the buffer tank 151 reaches the height of the liquid level sensor 154, the ink supply control unit 209 controls the pump P0 to replenish the ink from the main tank 141 to the buffer tank 151. Stop.

A first flow path 152 and a second flow path 153 exist on the downstream side of the buffer tank 151. The first flow path 152 is an ink flow path forming an ink circulation path (liquid circulation path) described later, and the second flow path 153 is a flow path for taking in air and is an air circulation path described later. (Details will be described later). As shown in FIG. 9A, the first flow path 152 is provided below the second flow path 153 in the vertical direction (gravity direction). As a result, the first flow path 152 is connected to the ink layer (liquid layer) in the buffer tank 151, while the second flow path 153 is connected to the air layer in the buffer tank 151. .. The first flow path 152 and the second flow path 153 merge on the downstream side to form one flow path. Here, the flow path on the downstream side of the confluence of the first flow path 152 and the second flow path 153 and between the confluence point and the recording head 8 is the third flow path 1001 (FIG. 10). See). Further, the flow path between the recording head 8 and the buffer tank 151 on the downstream side of the recording head 8 is defined as a fourth flow path 1002 (see FIG. 10).

The first flow path 152 is provided with the first flow path switching mechanism V1, and the second flow path is provided with the second flow path switching mechanism V2. The first flow path switching mechanism V1 and the second flow path switching mechanism V2 are mechanisms for switching the flow path to be used between the first flow path 152 and the second flow path 153. In the example, a valve is adopted as these flow path switching mechanisms. Here, a case where two valves are used as the flow path switching mechanism is shown, but as shown in FIG. 9B, it is provided at the confluence of the first flow path 152 and the second flow path 153. It may be in the form of using one flow path switching mechanism V.

The recording head 8 includes an ink ejection unit 80, a circulation unit 81, and a negative pressure control unit 82. The ink ejection unit 80 has a structure for ejecting ink droplets according to ejection data. In this embodiment, a heater is provided for each recording element, a film is boiled in the ink by applying a voltage to the heater, and the ink is discharged from the ejection port according to the growth energy of bubbles. do. The negative pressure control unit 82 adjusts the ink ejection unit 80 so that the ink flows in a normal direction at an appropriate pressure. The ink circulation unit 81 controls the supply of ink from the buffer tank 151 to the negative pressure control unit 82 and the collection of ink from the ink ejection unit 80 to the buffer tank 151.

The ink supplied from the buffer tank 151 to the circulation unit 81 is supplied to the negative pressure control unit 82 via the filter 811. The negative pressure control unit 82 includes a negative pressure control unit H that discharges ink at a high pressure and a negative pressure control unit L that discharges ink at a low pressure. The ink discharged from the negative pressure control unit H and the ink discharged from the negative pressure control unit L are supplied to the ink ejection unit 80 via the circulation unit 81 by different routes.

In the ink ejection unit 80, a plurality of recording element substrates 80a in which a plurality of nozzles are arranged in the y direction are further arranged in the y direction to form a long nozzle array. In addition, the common supply flow path 80b for guiding the ink supplied at high pressure by the negative pressure control unit H and the common recovery flow path 80c for guiding the ink supplied at low pressure by the negative pressure control unit L are also ink ejection. It is formed in the unit 80. Further, each recording element substrate 80a is formed with an individual flow path connected to the common supply flow path 80b and an individual flow path connected to the common recovery flow path 80c. Since a differential pressure (pressure difference) is generated by the two negative pressure control units, the two negative pressure control units flow into the individual recording element substrates 80a from the common supply flow path 80b having a high pressure, and the common supply flow path 80c having a low pressure. A flow of ink is generated that flows out to. Then, when the ejection operation is performed on the recording element substrate 80a, a part of the circulating ink is consumed by the ejection, but the remaining ink is returned to the circulation unit 81 through the common recovery flow path 80c, and the circulation pump P1 is operated. After that, it is returned to the buffer tank 151.

In such a circulation type ink supply system, since the heat generated in the ejection operation of the recording element substrate 80a is taken away by the circulating ink, it is possible to suppress the ejection failure due to the heat storage even if the ejection operation is continuously performed. can. In addition, since the bubbles, thickening ink, and foreign matter generated by the ejection operation are less likely to stagnate, the ejection state of the nozzle can be maintained satisfactorily.

In particular, since the bubbles generated by the ejection operation have the property of moving upward, when the recording operation is performed with the ejection port surface 8a, that is, the ink ejection unit 80 tilted as in the present embodiment, a specific recording is performed. Bubbles may stay in the element substrate 80a or a specific discharge port. However, if the circulation type ink supply system is adopted, the generated bubbles can be reliably collected through the common collection flow path 80c, so that the degree of freedom in the posture of the recording head 8 during the ejection operation is increased. As a result, the recording position as shown in FIG. 3 becomes possible, and the device can be miniaturized.

However, on the other hand, at the maintenance position, it is desirable that the discharge port surface 8a is horizontal so that the influence of gravity acts evenly on the individual recording element substrate 80a and each discharge port. Therefore, in the recording head 8, it is necessary to appropriately move between the standby position shown in FIG. 1, the recording position shown in FIG. 3, and the maintenance position shown in FIG. 7, and a simple and short-time movable configuration is provided. Desired.

<About the operation of the circulating ink supply system during recording>
The operation of the circulating ink supply system during recording will be described. FIG. 10A is a diagram showing the operation of the circulating ink supply system during recording. As shown in FIG. 10A, the valve of the first flow path switching mechanism V1 is open and the valve of the second flow path switching mechanism V2 is closed during recording. Therefore, in this case, the ink flowing out of the buffer tank 151 is supplied to the recording head 8 through the first flow path 152 and the third flow path 1001. A part of the ink supplied to the recording head 8 is consumed for recording, and the remaining ink that is not consumed flows out from the recording head 8. The ink flowing out of the recording head 8 is returned to the buffer tank 151 through the fourth flow path 1002. After that, the ink flows out of the buffer tank 151 again. During recording in this way, the circulation path (ink) through which the ink circulates through the buffer tank 151, the first flow path 152, the third flow path 1001, the recording head 8, and the fourth flow path 1002. (Called a circulation path) is constructed.

<About the operation of the circulating ink supply system in the ink recovery mode>
The operation of collecting the ink remaining in the circulation system and collecting the ink in the buffer tank 151 (operation in the ink recovery mode) will be described. When the recording head is replaced due to a failure or the like, the ink in the circulation system is collected and collected in the buffer tank 151, and then the recording head is replaced, so that the ink can be used without waste. Further, when moving the inkjet recording device 1, it is desirable to temporarily collect the ink in the circulation system and collect it in the buffer tank 151 in order to avoid ink leakage from the recording head 8.

FIG. 10B is a diagram showing the operation in the ink recovery mode. As shown in FIG. 10B, the valve of the first flow path switching mechanism V1 is closed and the valve of the second flow path switching mechanism V2 is open during operation in the ink recovery mode. Therefore, in this case, the air in the buffer tank 151 is sent to the third flow path 1001 through the second flow path 153, and the ink in the circulation system is pushed out to the buffer tank 151 by this air. Here, since the second flow path 153 is provided at a position higher than the ink liquid level, the ink extruded into the buffer tank 151 is not sent out to the circulation system again. As described above, in the ink recovery mode, air is generated by the buffer tank 151 (the air layer), the second flow path 153, the third flow path 1001, the recording head 8, and the fourth flow path 1002. A circulating circulation path (called an air circulation path) is constructed.

In the present embodiment, the ink in the circulation system is collected by sending the undried air in the ink tank into the flow path, whereby the air is taken in from the outside of the inkjet recording device and sent into the flow path. In comparison with the above, it is possible to suppress the evaporation of the ink.

<Ink filling process in the initial state>
The ink filling process in the initial state of the inkjet recording apparatus 1 will be described with reference to FIGS. 11 and 12. The following processing is started, for example, when the power of the inkjet recording device 1 is turned on and when the main tank 141 is attached. In the initial state, it is assumed that both the valve which is the first flow path switching mechanism V1 and the valve which is the second flow path switching mechanism V2 are closed.

In step S1101, the ink supply control unit 209 operates the pump P0 to send the ink stored in the main tank 141 to the buffer tank 151 (see FIG. 12A). As a result, ink accumulates in the buffer tank 151, and the height of the ink liquid level reaches the height of the liquid level sensor 154 at a certain timing.

In step S1102, the ink supply control unit 209 detects that the ink liquid level in the buffer tank 151 has reached the height of the liquid level sensor 154. In this case, the ink supply control unit 209 stops the operation of the pump P0 and stops the ink supply from the main tank 141 to the buffer tank 151 (see FIG. 12B).

In step S1103, the ink supply control unit 209 opens the valve (first flow path switching mechanism V1) in the first flow path 152 and operates the pumps P1 and P2. As a result, the ink flows into the first flow path 152, the third flow path 1001, the recording head 8, and the fourth flow path 1002, which form the ink circulation path, and is filled. Further, the height of the ink liquid level in the buffer tank 151 is lowered (see FIG. 12C).

In step S1104, the ink supply control unit 209 sends the ink stored in the main tank 141 to the buffer tank 151 by operating the pump P0 again (see FIG. 12D).

In step S1105, the ink supply control unit 209 detects that the ink liquid level in the buffer tank 151 has reached the height of the liquid level sensor 154. In this case, the ink supply control unit 209 stops the operation of the pump P0 and stops the ink supply from the main tank 141 to the buffer tank 151 (see FIG. 12E). The above is the content of the ink filling process in the initial state according to the present embodiment.

<Processing in ink recovery mode>
The process executed in the ink recovery mode will be described with reference to FIGS. 13 and 14. The processing in the ink recovery mode is started at a timing when, for example, the user instructs the ink in the ink circulation path to be collected and collected in the buffer tank 151 via the operation panel 104.

In step S1301, the ink supply control unit 209 performs a switching process of the flow path used. Specifically, the valve in the first flow path 152 (first flow path switching mechanism V1) is closed, and the valve in the second flow path 153 (second flow path switching mechanism V2) is opened (. See FIG. 14 (a)). As a result, the second flow path 153 will be used instead of the first flow path 152 thereafter.

In step S1302, the ink supply control unit 209 operates the pumps P1 and P2 to send the air in the buffer tank 151 to the third flow path 1001 through the second flow path 153. As a result, ink is drained from the second flow path 153, the third flow path 1001, the recording head 8, and the fourth flow path 1002 that form the air circulation path (see FIG. 14B). The above is the content of the process executed in the ink recovery mode according to the present embodiment.

The second flow path 153 is further than the maximum (maximum height) of the ink liquid level assumed when the ink in the circulating ink supply system is collected in the buffer tank 151. It is installed at a high position. The maximum height means that the first flow path 152, the third flow path 1001, the fourth flow path 1002, and the recording head 8 are filled with ink, and the ink liquid level is set to the height of the liquid level sensor 154. This is the height at which the ink converges when the ink is concentrated in the buffer tank 151 from the reached state.

[Other Examples]
The present invention supplies a program that realizes one or more functions of the above-described embodiment to a system or device via a network or storage medium, and one or more processors in the computer of the system or device reads and executes the program. It can also be realized by the processing to be performed. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

1 Inkjet recording device 8 Recording head 81 Circulation unit 151 Buffer tank 152 First flow path 153 Second flow path 1001 Third flow path 1002 Fourth flow path

Claims (16)

A tank to hold the liquid and
A recording head that discharges the liquid and
With the first flow path connected to the liquid layer in the tank,
A second flow path connected to the air layer in the tank,
A third flow path connecting the confluence of the first flow path and the second flow path and the recording head, and a third flow path.
A fourth flow path connecting the recording head and the tank,
A circulation means provided in the third flow path for circulating the liquid or air in a circulation path including the tank and the recording head.
A recording device including a switching means for making either one of the first flow path and the second flow path usable. A tank to hold the liquid and
A recording head that discharges the liquid and
With the first flow path connected to the liquid layer in the tank,
A second flow path connected to the air layer in the tank,
A third flow path connecting the confluence of the first flow path and the second flow path and the recording head, and a third flow path.
A fourth flow path connecting the recording head and the tank,
A circulation means provided in the fourth flow path for circulating the liquid or air in a circulation path including the tank and the recording head.
A recording device including a switching means for making either one of the first flow path and the second flow path usable. The recording device according to claim 1 or 2, wherein the liquid in the circulation path is collected in the tank by making the second flow path usable by the switching means. A tank to hold the liquid and
A recording head that discharges the liquid and
With the first flow path connected to the liquid layer in the tank,
A second flow path connected to the air layer in the tank,
A third flow path connecting the confluence of the first flow path and the second flow path and the recording head, and a third flow path.
A fourth flow path connecting the recording head and the tank,
A circulation means for circulating the liquid or air in a circulation path including the tank and the recording head.
A switching means for making either one of the first flow path and the second flow path usable is provided.
A recording device characterized in that the liquid in the circulation path is collected in the tank by making the second flow path usable by the switching means. The switching means according to claims 1 to 4, wherein the switching means includes a first valve capable of opening and closing the first flow path and a second valve capable of opening and closing the second flow path. The recording device according to any one of the following items. With the first valve open and the second valve closed, the tank, the first flow path, the third flow path, the recording head, and the fourth flow path. The recording device according to claim 5, wherein a liquid circulation path through which the liquid circulates is formed in the order of the paths. The recording device according to claim 6, wherein the liquid is discharged from the recording head in a state where the liquid circulation path is formed. With the first valve closed and the second valve open, the tank, the second flow path, the third flow path, the recording head, and the fourth flow. The recording device according to claim 6 or 7, wherein an air circulation path through which air circulates is formed in the order of the paths. The recording device according to claim 8, wherein the liquid is recovered from the recording head to the tank by circulating air in the air circulation path. Further having a liquid level sensor for detecting the height of the liquid level in the tank,
The recording device according to claim 8 or 9 , wherein when the liquid circulation path is filled with the liquid, the height of the liquid level is controlled so as not to exceed the height of the liquid level sensor. .. The first flow path, the third flow path, the recording head, and the fourth flow path forming the liquid circulation path are filled with the liquid, and the height of the liquid level in the tank. The second flow path is connected to a higher position in the tank than the height of the liquid level reached when the liquid is recovered from the state where the liquid level sensor reaches the height of the liquid level sensor into the tank. The recording device according to claim 10 , wherein the recording device is provided. A tank to hold the liquid and
A recording head that discharges the liquid and
With the first flow path connected to the liquid layer in the tank,
A second flow path connected to the air layer in the tank,
A third flow path connecting the confluence of the first flow path and the second flow path and the recording head, and a third flow path.
A fourth flow path connecting the recording head and the tank,
A method for controlling a recording device, which is provided in the third flow path and includes a circulation means for circulating the liquid or air in a circulation path including the tank and the recording head.
A control method comprising a switching step for making either one of the first flow path and the second flow path usable. A tank to hold the liquid and
A recording head that discharges the liquid and
With the first flow path connected to the liquid layer in the tank,
A second flow path connected to the air layer in the tank,
A third flow path connecting the confluence of the first flow path and the second flow path and the recording head, and a third flow path.
A fourth flow path connecting the recording head and the tank,
A method for controlling a recording device, which is provided in the fourth flow path and includes a circulation means for circulating the liquid or air in a circulation path including the tank and the recording head.
A control method comprising a switching step for making either one of the first flow path and the second flow path usable. The control method according to claim 12 or 13, further comprising a step of collecting the liquid in the circulation path into the tank by making the second flow path available in the switching step. .. A tank to hold the liquid and
A recording head that discharges the liquid and
With the first flow path connected to the liquid layer in the tank,
A second flow path connected to the air layer in the tank,
A third flow path connecting the confluence of the first flow path and the second flow path and the recording head, and a third flow path.
A fourth flow path connecting the recording head and the tank,
A method of controlling a recording device comprising a circulation means for circulating the liquid or air in a circulation path including the tank and the recording head.
A switching step for making either one of the first flow path and the second flow path usable,
A control method comprising: a step of collecting the liquid in the circulation path into the tank by making the second flow path usable in the switching step. A program for causing a computer to perform the method according to any one of claims 12 to 15.

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