Recording device, control method, storage medium, and program

Abstract

This recording device comprises: a forming means for forming a liquid chamber into which a liquid is introduced from a liquid container, and which stores the liquid and supplies the liquid to an ejecting means for ejecting the liquid onto a recording medium, and a pressure chamber adjacent to the liquid chamber; a wall body which demarcates the liquid chamber and the pressure chamber, and which is displaced in accordance with the pressure in the pressure chamber to change the volume of the liquid chamber; a pressure adjusting means which communicates with the pressure chamber via a communicating passage and which, by adjusting the pressure in the pressure chamber, is capable of switching between the introduction of the liquid into the liquid chamber and the supply of the liquid to the ejecting means; and a valve provided in the communicating passage. The valve allows communication between the pressure adjusting means and the pressure chamber in an open state, blocks communication between the pressure adjusting means and the pressure chamber in a closed state, and maintains the pressure state of the pressure chamber.

Description

Recording device, control method, storage medium, and program

[0001] The present disclosure relates to a recording device.

[0002] In order to achieve stable ink ejection performance, a recording device has been proposed that supplies pressurized ink to an ejection head. Patent Document 1 discloses a device that has a flow path unit that supplies pressurized ink between a container that stores ink and a liquid ejection head. The flow path unit increases or decreases the volume of a liquid feed chamber to introduce ink from the container to the liquid feed chamber and to feed ink from the liquid feed chamber to the liquid ejection head.

[0003] Japanese Patent Application Laid-Open No. 2018-34335

[0004] In a configuration in which the volume of the liquid chamber that contains the ink is increased or decreased to introduce ink and supply it to the recording head, if the introduction of ink into the liquid chamber begins at the time when it becomes necessary to supply ink to the recording head, the supply to the recording head may be delayed, resulting in long downtime.

[0005] The present disclosure provides techniques that can reduce downtime.

[0006] According to the present disclosure, there is provided a recording device comprising: a liquid chamber that receives liquid from a liquid container and stores the liquid to be supplied to an ejection means that ejects the liquid onto a recording medium; and a forming means that forms a pressure chamber adjacent to the liquid chamber; a wall that separates the liquid chamber from the pressure chamber and that changes the volume of the liquid chamber by displacing according to the pressure of the pressure chamber; a pressure adjustment means that communicates with the pressure chamber via a communication passage and is capable of switching between introducing liquid into the liquid chamber and supplying liquid to the ejection means by adjusting the pressure of the pressure chamber; and a valve provided in the communication passage, wherein the valve communicates between the pressure adjustment means and the pressure chamber in an open state, and blocks communication between the pressure adjustment means and the pressure chamber in a closed state, thereby maintaining the pressure state of the pressure chamber.

[0007] According to the present disclosure, it is possible to provide a technique that can reduce downtime.

[0008] 15 is a perspective view of a recording apparatus according to an embodiment of the present disclosure. FIG. 16 is an explanatory diagram of a supply unit and a recovery unit for supplying liquid from a container to a discharge head. FIG. 17 is an explanatory diagram showing an example of the operation of the supply unit. FIG. 18 is an explanatory diagram showing an example of the operation of the supply unit. A flowchart showing an example of the processing of a control circuit. FIG. 19 is an explanatory diagram showing another example of the operation of the supply unit. A flowchart showing an example of the processing of the control circuit. A flowchart showing an example of the processing of the control circuit. FIG. 19 is an explanatory diagram showing another example of the configuration of the supply unit. FIG. 20 is an explanatory diagram showing another example of the configuration of the supply unit. FIG. 21 is an explanatory diagram showing an example of the configuration of a state control valve. FIG. 22 is an explanatory diagram of the operation of the state control valve of FIG. 12. FIG. 23 is an explanatory diagram of another example of the configuration of the state control valve. FIG. 24 is an explanatory diagram of the operation of the state control valve of FIG. 15.

[0009] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the claims. Although multiple features are described in the embodiments, not all of these multiple features are required, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

[0010] First Embodiment Overview of Recording Apparatus Fig. 1 is a perspective view of a recording apparatus 1 according to an embodiment of the present disclosure. The recording apparatus 1 is an inkjet recording apparatus that ejects ink as a liquid to record on a recording medium. In the drawing, arrows X and Y indicate horizontal directions that are orthogonal to each other, and arrow Z indicates the up-down direction (direction of gravity). The X direction is the width direction (left-right direction) of the recording apparatus 1. The Y direction is the depth direction of the recording apparatus 1.

[0011] It should be noted that "recording" not only includes the formation of meaningful information such as characters and figures, but also includes the formation of images, designs, patterns, etc. on a recording medium, whether meaningful or insignificant, or the processing of the medium, regardless of whether the information is visible to humans. In addition, although sheet-like paper is assumed as the "recording medium" in this embodiment, it may also be cloth, plastic film, etc.

[0012] The recording device 1 includes an ejection head 4 that ejects liquid. The ejection head 4 is a recording head that ejects liquid contained in containers 5Bk, 5C, 5M, and 5Y (hereinafter referred to as containers 5 when collectively referred to or when not distinguished) onto a recording medium to record an image. The ejection head 4 has an ejection surface on which a plurality of nozzles that eject ink are formed. Each nozzle is provided with, for example, an electrothermal conversion element (heater), which is heated by passing electricity through the element to cause the ink to foam, and the resulting foaming energy is used to eject the ink.

[0013] The containers 5 are ink tanks that contain ink as a liquid, and the four containers 5 contain different types of ink. In this embodiment, container 5Bk contains black ink, container 5C contains cyan ink, container 5M contains magenta ink, and container 5Y contains yellow ink. The number of ink types is not limited to four as in this embodiment, and may be one type or multiple types other than four. The number of containers 5 may be equal to or greater than the number corresponding to the types of liquid ink. The containers 5 may be in the form of a rigid resin box or a flexible bag (pack).

[0014] The ejection head 4 is mounted on a carriage 2. The carriage 2 is reciprocated in the X direction (main scanning direction) by a drive unit 6. The drive unit 6 includes two pulleys (a drive pulley and a driven pulley) 6a spaced apart in the X direction, an endless belt 6b wound around the two pulleys 6a, and a carriage motor (not shown) that serves as a drive source for rotating the drive pulley. The carriage 2 is connected to the endless belt 6b, and moving the endless belt 6b causes the carriage 2 to move in the X direction. As the carriage 2 moves, an image is recorded by ejecting ink from the ejection head 4 onto a recording medium. This operation is sometimes called recording scanning.

[0015] As described above, the recording apparatus 1 of this embodiment is a serial type inkjet recording apparatus in which the ejection head 4 is mounted on the reciprocating carriage 2. However, the present disclosure is also applicable to other recording apparatuses, such as inkjet recording apparatuses equipped with a so-called full-line ejection head (recording head) provided with multiple nozzles that eject liquid in an area corresponding to the width of the recording medium.

[0016] The recording device 1 includes a paper feed tray 9 on which recording media are stacked before recording and a paper discharge tray 8 on which recording media are discharged after recording. The recording media stacked on the paper feed tray 9 are transported to a transport unit 7 by a feeding mechanism (not shown). The transport unit 7 is a mechanism that transports the recording media in the Y direction (sub-scanning direction).

[0017] The transport unit 7 includes a transport roller 7a, a pinch roller 7b that is in pressure contact with the transport roller 7a, and a transport motor (not shown) that is a drive source for rotating the transport roller 7a. The recording medium is sandwiched in the nip between the transport roller 7a and the pinch roller 7b. The rotation of the transport roller 7a intermittently transports the recording medium between the platen 3 and the ejection head 4. The recording operation is performed by alternately repeating the transport operation of the recording medium by the transport unit 7 and recording scanning. The recorded recording medium is discharged to the paper output tray 8.

[0018] A recovery unit 10 is provided at one end of the Y-direction movement range of the carriage 2. The recovery unit 10 maintains and recovers the liquid ejection performance of the recording head 2 when the carriage 2 is at a predetermined stop position (home position).

[0019] <Supply Unit> Next, a description will be given of a unit for supplying liquid from the container 5 to the ejection head 4. FIG.

[0020] The recovery unit 10 includes a cap member 10a. The cap member 10a is a member that covers the ejection surface 4a of the ejection head 4. The recovery unit 10 is equipped with an operating mechanism (not shown), and the cap member 10a can be moved by the operating mechanism between a capping position that covers the ejection surface 4a and an uncapping position. A plurality of nozzles 4b that eject liquid are opened on the ejection surface 4a. The cap member 10a covers the ejection surface 4a, thereby preventing the nozzles 4b from drying out. The recovery unit 10 also has a pump 10b. The pump 10b can create a negative pressure in the internal space of the cap member 10a and suck liquid from the ejection head 4 and discharge it into a waste liquid tank 10c. This recovery process can remove thickened substances and the like that have adhered to the nozzles 4b, restoring their liquid ejection performance.

[0021] The supply unit 11 is a supply mechanism that supplies liquid from the container 5 to the ejection head 4. A supply unit 11 is provided for each of the containers 5Bk, 5C, 5M, and 5Y. Therefore, the recording apparatus 1 of this embodiment has four supply units 11. One of the four supply units 11 is illustrated in Figure 2.

[0022] The supply unit 11 includes an intermediate tank 20, a buffer tank 30, a pressure adjustment unit 40, and a state control valve 15. The intermediate tank 20 is connected to the container 5 via a pipe 16. A backflow prevention valve 12 is provided in the pipe 16. The buffer tank 30 is connected to the intermediate tank 20 via a pipe 17. A backflow prevention valve 13 is provided in the pipe 17. The buffer tank 30 is connected to the ejection head 4 via a pipe 18. A filter 14 that removes foreign matter from the liquid is provided in the pipe 18. The pressure adjustment unit 40 is connected to the intermediate tank 20 via a pipe 19. The state control valve 15 is provided in the pipe 19.

[0023] The pipes 16 to 18 form a flow path for the liquid. The pipe 19 is a communication path that connects the pressure adjustment unit 40 and the intermediate tank 20, and forms a flow path for the fluid used for pressure control. In this embodiment, the fluid is a gas, particularly air. The pipes 16 to 19 are made of, for example, flexible tubes.

[0024] The liquid in the container 5 is introduced into the intermediate tank 20 via the pipe 16. In the direction of introducing the liquid, the container 5 is located upstream and the intermediate tank 20 is located downstream. The backflow prevention valve 12 is provided in the pipe 16 upstream of the intermediate tank 20, and is a one-way valve (check valve) that prevents the liquid from flowing back from the intermediate tank 20 side to the container 5 side.

[0025] The liquid in the intermediate tank 20 is supplied to the discharge head 4 via the pipe 17, the buffer tank 30, and the pipe 18. In the liquid supply direction, the intermediate tank 20 is located upstream, and the buffer tank 30 and the discharge head 4 are located downstream. The buffer tank 30 is located upstream of the discharge head 4. The backflow prevention valve 12 is provided in the pipe 17 downstream of the intermediate tank 20, and is a one-way valve (check valve) that prevents the liquid from flowing back from the buffer tank 30 side to the intermediate tank 20 side.

[0026] The intermediate tank 20 performs an introducing operation of introducing the liquid contained in the container 5 by suction, and a supply operation of sending the introduced liquid toward the ejection head 4. In other words, the intermediate tank 20 functions as a pump.

[0027] The intermediate tank 20 includes a forming unit 21 that forms a liquid chamber 22 and a pressure chamber 23. The forming unit 21 is a hollow body that forms an outer wall that defines the liquid chamber 22 and the pressure chamber 23. The liquid chamber 22 contains the liquid to be supplied to the ejection head 4. Liquid is introduced into the liquid chamber 22 from the container 5. The pressure chamber 23 is formed adjacent to the liquid chamber 22 via a wall 24. The wall 24 separates the liquid chamber 22 from the pressure chamber 23. The wall 24 can also be said to be part of the peripheral wall that defines the liquid chamber 22 and the pressure chamber 23. The wall 24 is a diaphragm that changes the volume of the liquid chamber 22 by displacing in accordance with the pressure of the pressure chamber 23. In this embodiment, the wall 24 is made of a flexible sheet that elastically deforms in accordance with the pressure difference between the liquid chamber 22 and the pressure chamber 23.

[0028] The intermediate tank 20 is provided with a biasing member 25 that constantly biases the wall 24 in a direction that reduces the volume of the liquid chamber 22. In this embodiment, the biasing member 25 is an elastic member, particularly a coil spring, that is arranged in the pressure chamber 23 between the inner wall of the pressure chamber 23 and the wall 24. The biasing of the biasing member 25 enables the liquid to be pressurized and supplied from the liquid chamber 22 to the ejection head 4 and the buffer tank 30. The pressure chamber 23 is in communication with the pressure adjustment unit 40 via a pipe 19.

[0029] The pressure adjustment unit 40 includes an exhaust unit 41 connected to the pipe 19, and an atmosphere release unit 42. The exhaust unit 41 is a negative pressure generating source that reduces the pressure by exhausting air from the pressure chamber 23 through the pipe 19, and in this embodiment, is an electric pump. The atmosphere release unit 42 includes a pipe 44 branching off from the pipe 19, and an atmosphere release valve 43 provided on the pipe 44. An end of the pipe 44 is open to the atmosphere. The atmosphere release valve 43 is a control valve that includes an actuator such as a motor and opens and closes the pipe 44.

[0030] When the pressure chamber 23 is decompressed by the discharge unit 41, the wall 24 is displaced toward the pressure chamber 23 while compressing the biasing member 25, and the volume of the liquid chamber 22 is expanded. As a result, liquid is sucked into the liquid chamber 22 from the container 5. When the state control valve 15 is open and the atmosphere release valve 43 is opened, the pressure chamber 23 becomes atmospheric pressure. The biasing force of the biasing member 25 displaces the wall 24 toward the liquid chamber 22, and the volume of the liquid chamber 22 is reduced. As a result, liquid is sent from the liquid chamber 22 to the ejection head 4 or the buffer tank 30.

[0031] The state control valve 15 is a control valve that includes an actuator such as a solenoid and opens and closes the pipe 19. When the state control valve 15 is in an open state, communication is established between the pressure adjustment unit 40 and the pressure chamber 23. When the state control valve 15 is in a closed state, communication between the pressure adjustment unit 40 and the pressure chamber 23 is blocked, the pressure chamber 23 becomes airtight, and the pressure state of the pressure chamber 23 is maintained.

[0032] The buffer tank 30 is a tank that stores liquid and is interposed between the intermediate tank 20 and the ejection head 4. By providing the buffer tank 30, it is possible to respond to fluctuations in the amount of liquid consumed by the ejection head 4. The buffer tank 30 includes a forming unit 31 that forms a liquid chamber 32 and an atmosphere communication chamber 33.

[0033] The forming unit 31 is a hollow body that forms an outer wall that defines the liquid chamber 32 and the atmosphere communication chamber 23. The liquid chamber 32 contains the liquid to be supplied to the ejection head 4. Liquid is introduced into the liquid chamber 32 from the intermediate tank 20. The atmosphere communication chamber 33 is formed adjacent to the liquid chamber 32 via a wall 34. The wall 34 separates the liquid chamber 32 from the atmosphere communication chamber 33. The wall 34 can also be said to be part of the peripheral wall that defines the liquid chamber 32 and the atmosphere communication chamber 33. The wall 34 is a diaphragm that changes the volume of the liquid chamber 32. In this embodiment, the wall 34 is made of an elastically deformable flexible sheet.

[0034] The buffer tank 30 is provided with a biasing member 35 that constantly biases the wall 34 in a direction that reduces the volume of the liquid chamber 32. In this embodiment, the biasing member 35 is an elastic member, particularly a coil spring, that is arranged in the atmosphere communication chamber 33 between the inner wall of the atmosphere communication chamber 33 and the wall 34. The biasing force of the biasing member 35 enables the liquid to be pressurized and supplied from the liquid chamber 32 to the ejection head 4. The biasing force of the biasing member 35 can be designed to be lower than the biasing force of the biasing member 25. An opening 31a that connects the atmosphere communication chamber 33 to the atmosphere is formed in a portion of the peripheral wall of the atmosphere communication chamber 33.

[0035] The buffer tank 30 is provided with a detection unit 51 that detects the remaining amount of liquid contained in the buffer tank 30. In this embodiment, the detection unit 51 is an optical sensor disposed in the atmosphere communication chamber 33, and includes a light-emitting element 51a and a light-receiving element 51b. A detection piece 36 is fixed to the wall body 34. In this embodiment, the detection piece 36 is an axially shaped member that passes through the biasing member 35, and is displaced together with the wall body 34.

[0036] When the remaining amount of liquid contained in the liquid chamber 32 is large, that is, when the volume of the liquid chamber 32 is large, the detection piece 36 is positioned relatively lower, between the light-emitting element 51a and the light-receiving element 51b, as shown in the example of Figure 2. The detection piece 36 is positioned on the optical axis of light traveling from the light-emitting element 51a to the light-receiving element 51b, and the light is blocked by the detection piece 36. As a result, the amount of light received by the light-receiving element 51b decreases.

[0037] When the amount of liquid remaining in the liquid chamber 32 is small, i.e., when the volume of the liquid chamber 32 is small, the detection piece 36 is positioned relatively high and escapes from between the light-emitting element 51a and the light-receiving element 51b. The light from the light-emitting element 51a to the light-receiving element 51b is not blocked by the detection piece 36, and the amount of light received by the light-receiving element 51b increases. This mechanism allows the detection unit 51 to detect when the amount of liquid remaining in the liquid chamber 32 has fallen below a predetermined amount. Here, the detection unit 51 may be configured to detect when the amount of liquid remaining is almost 0%, or when the amount is low (for example, 30%).

[0038] The operation of the supply unit 11 is controlled by a control circuit 50. The control circuit 50 may be an electronic circuit specialized for controlling the supply unit 11, or may be a circuit that also includes an electronic circuit that controls all or part of the recording device 1.

[0039] The control circuit 50 includes at least one processor, at least one storage device, and at least one input / output interface. The storage device is, for example, a semiconductor memory such as RAM or ROM. The processor executes programs stored in the storage device. The input / output interface inputs and outputs signals between the processor and external devices (sensors, actuators, etc.) and other control circuits included in the recording device 1. The external devices include the detection unit 51 and the actuators of the exhaust unit 41, the atmosphere release valve 43, and the state control valve 15.

[0040] <Example of Operation> An example of operation of the supply unit 11 will be described with reference to Fig. 3 and Fig. 4. Under the control of the control circuit 50, the supply unit 11 can perform the operations exemplified in Figs.

[0041] 3 shows a state in which the liquid contained in the buffer tank 30 is consumed by the ejection head 4 as the ejection head 4 ejects the liquid. The biasing member 35 biases the wall 34 in a direction that reduces the liquid chamber 32. The state control valve 15 is closed, and the pressure chamber 23 of the intermediate tank 20 is maintained in a negative pressure state. A sufficient amount of liquid is contained in the liquid chamber 22. The atmosphere release valve 43 is open, and the discharge unit 41 is stopped.

[0042] The supply of liquid from the intermediate tank 20 is started when a supply start condition is met. In this embodiment, the supply start condition is that the detection unit 51 detects that the remaining amount has fallen to a predetermined amount or less.

[0043] State ST2 in Figure 3 shows a state in which the supply of liquid from the intermediate tank 20 has begun. The state control valve 15 is switched to the open state. The pressure chamber 23 is released from a negative pressure state to the atmosphere. The wall body 24 is pushed up by the biasing member 25, and the volume of the liquid chamber 22 is reduced. As a result, the liquid contained in the liquid chamber 22 is supplied to the buffer tank 30 and the ejection head 4. Because the pressure chamber 23 is released from a negative pressure state to the atmosphere in a short time, the liquid contained in the liquid chamber 22 is supplied to the buffer tank 30 and the ejection head 4 in a short time.

[0044] When the amount of liquid supplied to the liquid chamber 32 exceeds the amount of liquid consumed by the ejection head 4, liquid is stored in the liquid chamber 32. The wall 34 displaces downward while compressing the biasing member 35, expanding the volume of the liquid chamber 32. State ST3 in Figure 3 shows a state in which a sufficient amount of liquid has been supplied to the liquid chamber 32. Because the detection piece 36 displaces downward together with the wall 34, the detection unit 51 no longer detects that the remaining amount is below a predetermined amount.

[0045] Introduction of liquid into the intermediate tank 20 starts when an introduction start condition is met. In this embodiment, the introduction start condition is when the detection unit 51 no longer detects that the remaining amount is below a predetermined amount. The introduction start condition may also be met after a predetermined time has elapsed since the detection unit 51 no longer detects that the remaining amount is below the predetermined amount.

[0046] State ST4 in Figure 4 shows the state where introduction of liquid into the intermediate tank 20 has begun. The atmosphere release valve 43 is switched to a closed state. The discharge unit 41 is driven, and the pressure chamber 23 is depressurized. The wall body 24 displaces toward the pressure chamber 23 while compressing the biasing member 25, and the liquid chamber 22 expands. As a result, liquid is sucked from the container 5 into the liquid chamber 22.

[0047] The discharge unit 41 is driven for a predetermined time so that a sufficient amount of liquid is introduced into the liquid chamber 22. After the discharge unit 41 is stopped, as shown in state ST5 in Figure 4, the discharge unit 41 is stopped and the state control valve 15 is switched to a closed state. The pressure state of the pressure chamber 23 is maintained at a negative pressure state. The intermediate tank 20 enters a standby state, waiting for the supply of liquid to the buffer tank 30 and the ejection head 4. In this manner, the operations from state ST1 in Figure 3 to state ST5 in Figure 4 are repeated.

[0048] As described above, in this embodiment, as shown in state ST5 in FIG. 4 , the liquid chamber 22 can be kept filled with a sufficient amount of liquid while on standby. When liquid needs to be supplied to the buffer tank 30 and the ejection head 4, the state control valve 15 can be switched to the open state, as shown in state ST2 in FIG. 3 , allowing for instant liquid supply. This prevents the recording operation from being interrupted due to a lack of liquid supply to the ejection head 4, thereby reducing downtime. Since the remaining amount of liquid in the buffer tank 30 can be immediately replenished, the liquid capacity of the buffer tank 30 can be reduced. This also prevents the buffer tank 30 from being increased in size to reduce downtime, which would otherwise result in an increase in the size of the recording apparatus 1.

[0049] To maintain the negative pressure state of the pressure chamber 23, for example, it is conceivable to use an exhaust unit 41. However, if a motor-driven suction pump is used as the exhaust unit 41, for example, it becomes difficult to maintain the negative pressure state of the pressure chamber 23 when the drive is stopped due to air leakage inside the pump. Furthermore, continuously driving the suction pump is disadvantageous in terms of power consumption and noise. In this embodiment, the negative pressure state of the pressure chamber 23 can be maintained by the state control valve 15, thereby eliminating these disadvantages.

[0050] FIG. 5 is a flowchart showing an example of processing by the control circuit 50, and shows an example of control processing by the supply unit 11 to realize the operations of FIGS.

[0051] In step S1, the control circuit 50 closes the atmosphere release valve 43. In step S2, the control circuit 50 drives the exhaust unit 41 for a predetermined time and then stops driving it (state ST4 in FIG. 4). In step S3, the control circuit 50 closes the state control valve 15, and in step S4, the control circuit 50 opens the atmosphere release valve 43 (state ST5 in FIG. 4).

[0052] In step S5, the control circuit 50 acquires the detection result of the detection unit 51 and determines whether the remaining amount of liquid in the buffer tank 30 is equal to or less than a threshold. If the remaining amount is equal to or less than the threshold, the process proceeds to step S6. If the remaining amount is not equal to or less than the threshold, the process of step S5 is repeated. In step S6, the control circuit 50 switches the state control valve 15 to the open state (state ST2 in FIG. 3). After that, the process returns to step S1 and the same process is repeated.

[0053] Second Embodiment In the first embodiment, in a standby state in which the intermediate tank 20 waits for the supply of liquid to the buffer tank 30 or the like, the state control valve 15 is closed to maintain the pressure state of the pressure chamber 23 at a negative pressure. However, if the intermediate tank 20 is left in the standby state for a long period of time, negative pressure may act on the components of the intermediate tank 20 for a long period of time, causing deterioration of the components. Therefore, in the standby state, an operation to open the pressure chamber 23 to the atmosphere may also be performed. For convenience, the standby state operation in the first embodiment is referred to as a negative pressure standby operation, and the standby state operation in the present embodiment is referred to as an atmospheric pressure standby operation.

[0054] Figure 6 is an explanatory diagram of the atmospheric pressure standby operation. State ST11 in Figure 6 shows a state in which the liquid contained in the buffer tank 30 is consumed by the ejection head 4 as the ejection head 4 ejects liquid. The biasing member 35 causes the wall 34 to be displaced in a direction that reduces the liquid chamber 32. The state control valve 15 is closed, but the pressure chamber 23 of the intermediate tank 20 is at atmospheric pressure. There is almost no liquid remaining in the liquid chamber 22. The atmosphere release valve 43 is open, and the discharge unit 41 is stopped.

[0055] Introduction of liquid into the intermediate tank 20 is started when an introduction start condition is met. In this embodiment, the introduction start condition is that the detection unit 51 detects that the remaining amount has fallen to a predetermined amount or less.

[0056] State ST12 in Figure 6 shows the state in which introduction of liquid into the intermediate tank 20 has begun. The state control valve 15 is switched to the open state. The atmosphere release valve 43 is switched to the closed state. The discharge unit 41 is driven, and the pressure chamber 23 is depressurized. The wall body 24 is displaced toward the pressure chamber 23 while compressing the biasing member 25, and the liquid chamber 22 expands. As a result, liquid is sucked from the container 5 into the liquid chamber 22.

[0057] The discharge unit 41 is driven for a predetermined time so that a sufficient amount of liquid is introduced into the liquid chamber 22. After the discharge unit 41 is stopped, the atmosphere release valve 43 is switched to an open state, as shown in state ST13 in Figure 6. The pressure chamber 23 is released from a negative pressure state to the atmosphere. The wall body 24 is pushed up by the biasing member 25, and the volume of the liquid chamber 22 is reduced. As a result, the liquid contained in the liquid chamber 22 is supplied to the buffer tank 30 and the ejection head 4. Because the pressure chamber 23 is released from a negative pressure state to the atmosphere in a short time, the liquid contained in the liquid chamber 22 is supplied to the buffer tank 30 and the ejection head 4 in a short time.

[0058] Thereafter, as shown in state ST14 in Fig. 6, the state control valve 15 is switched to the closed state. The pressure state of the pressure chamber 23 is maintained at atmospheric pressure. The intermediate tank 20 enters a standby state, waiting for the supply of liquid to the buffer tank 30 and the ejection head 4. In this manner, the operation in Fig. 6 is repeated.

[0059] 7A is a flowchart showing an example of processing by the control circuit 50, particularly showing an example of processing for selecting between negative pressure standby operation and atmospheric pressure standby operation. In step S11, the control circuit 50 selects either the negative pressure standby operation or the atmospheric pressure standby operation as the standby operation. In step S12, the control circuit 50 executes the standby operation selected in step S11.

[0060] The standby operation may be selected based on, for example, the time period or the day of the week. During the time period or the day of the week when the recording operation is frequently performed, the control circuit 50 selects the negative pressure standby operation as the standby operation. For example, the control circuit 50 selects the negative pressure standby operation between 10:00 AM and noon and between 1:00 PM and 6:00 PM, and selects the atmospheric pressure standby operation during other time periods. Alternatively, for example, the control circuit 50 may select the negative pressure standby operation on weekdays and the atmospheric pressure standby operation on weekends. The execution frequency of the recording operation per unit time may be calculated and updated, and when the execution frequency falls below a threshold, the control circuit 50 may select the atmospheric pressure standby operation. Alternatively, the time (time period, day of the week) may be determined separately from the control circuit 50, and the control circuit 50 may acquire information for this determination before step S11.

[0061] FIG. 7B is a flowchart showing an example of processing by the control circuit 50, and shows an example of control processing by the supply unit 11 to realize the operation of FIG.

[0062] In step S21, the control circuit 50 acquires the detection result of the detection unit 51 and determines whether the remaining amount of liquid in the buffer tank 30 is equal to or less than a threshold. If the remaining amount is equal to or less than the threshold, the process proceeds to step S22. If the remaining amount is not equal to or less than the threshold, the process of step S21 is repeated. Here, the interval at which the process of step S21 is repeated can be set as appropriate.

[0063] In step S22, the control circuit 50 switches the atmosphere release valve 43 to the closed state, and in step S23, the control circuit 50 switches the state control valve 15 to the open state. Furthermore, in step S24, the control circuit 50 drives the exhaust unit 41 for a predetermined time and then stops driving it (state ST12 in FIG. 6). In step S25, the control circuit 50 switches the atmosphere release valve 43 to the open state (state ST13 in FIG. 6). In step S24, the state control valve 15 is switched to the closed state (state ST14 in FIG. 6). After that, the process returns to step S21 and the same processing is repeated.

[0064] In the first embodiment, the supply units 11 are individually provided for the respective containers 5, but it is also possible to share part of the configuration of the supply units 11. That is, for example, in a configuration having four supply units, one pressure adjustment unit 40 may be shared (Configuration Example 1), or two pressure adjustment units 40 may be provided, and one pressure adjustment unit 40 may be shared by two supply units (Configuration Example 3).

[0065] (Configuration Example 1) Fig. 8 is an explanatory diagram of a supply unit 11 showing one example. In the example shown, one pressure adjustment unit 40 is shared by four supply units 11. Each pipe 19 is connected to a common pipe 19A. In other words, each pipe 19 branches off from pipe 19A. Pipe 19A is formed of, for example, a flexible tube. The pressure adjustment unit 40 is connected to pipe 19A.

[0066] In this embodiment, when all four state control valves 15 are in the open state, the pressure adjustment unit 40 and each pressure chamber 22 of the four intermediate tanks 20 are in a state of communication. Therefore, the pressure adjustment unit 40 can simultaneously depressurize each pressure chamber 22 and release it to the atmosphere. On the other hand, when one of the four state control valves 15 is in the open state and the other three state control valves 15 are in the closed state, it is also possible to individually introduce or supply liquid from the container 5 corresponding to the state control valve 15 that is in the open state.

[0067] As an example of this operation, for example, an ink introduction operation of the corresponding color is performed for all four intermediate tanks 20 (state ST4 in FIG. 4 ). Subsequently, by closing all four state control valves 15, the negative pressure state (pressure state) of each pressure chamber 22 is maintained and the system waits (state ST5 in FIG. 4 ). Thereafter, by individually opening the corresponding state control valve 15 depending on the consumption of each color of ink, only the ink of that color can be supplied to the buffer tank 30 and the ejection head 4. For example, when the detection unit 51 detects a decrease in the remaining amount of ink in the buffer tank 30 corresponding to black ink, only the state control valve 15 corresponding to black ink is switched to the open state. As a result, black ink is supplied from the intermediate tanks 20 to the buffer tank 30 and the ejection head 4.

[0068] Such individual control can prevent oversupply, which occurs when ink of a color that does not need to be supplied to the buffer tank 30 or the ejection head 4 is supplied. More specifically, if excessive ink is supplied to the liquid chamber 31 of the buffer tank 30, the wall 34 may expand excessively and the biasing member 35 may be compressed excessively. This may result in the pressure of the ink being sent to the ejection head 4 becoming unexpectedly high due to the force (restoring force) exerted when these components return to their original states. As a result, the ink supply pressure may become too high, resulting in poor recording. The above-described individual control can prevent such situations and prevent poor recording, which may occur when the ink supply pressure exceeds the appropriate range. Furthermore, the tolerance for pressure loss within the piping 18 can be increased. That is, the ink viscosity and flow rate, which are parameters that contribute to pressure loss within the piping 18, can be increased within appropriate ranges. Therefore, by increasing the pigment concentration in the ink (increasing the ink viscosity) and increasing the ink flow rate, it is possible to improve the quality of printed images and productivity by increasing the printing speed. Furthermore, in the configuration example 1, the number of parts can be reduced, thereby making it possible to reduce the size and cost of the device.

[0069] (Configuration Example 2) Fig. 9 shows another configuration example. In Configuration Example 2 of Fig. 9, in addition to Configuration Example 1 of Fig. 8, one state control valve 15 is shared by multiple supply units 11. In Configuration Example 2 of Fig. 9, a total of two state control valves 15A and 15B are used. One state control valve 15A is shared by each supply unit 11 corresponding to containers 5Y, 5M, and 5C. A unique state control valve 15B is provided in the supply unit 11 corresponding to container 5Bk.

[0070] The state control valve 15A is arranged upstream (toward the pressure adjustment unit 40) of the branch point between the pipe 19A and the pipe 19 of each supply unit 11 corresponding to the containers 5Y, 5M, and 5C. The state control valve 15B is arranged downstream (toward the intermediate tank 20) ​​of the branch point between the pipe 19A and the pipe 19 of the supply unit 11 corresponding to the container 5Bk.

[0071] Configuration Example 2 is advantageous, for example, in a recording device 1 that uses black ink with a high pigment concentration to improve the quality of the black color in the recorded image. That is, a high-viscosity ink that causes a relatively large pressure loss in the piping 18 can be used for the black ink, and low-viscosity inks can be used for the other three colors. For the black ink, increasing the pigment concentration (increasing the ink viscosity) and increasing the ink flow rate can improve the quality of the recorded image and productivity by increasing the recording speed. Furthermore, Configuration Example 2 reduces the number of parts, thereby reducing the size and cost of the device and reducing the power consumption required to drive the state control valve.

[0072] (Configuration Example 3) Fig. 10 shows another configuration example. In Configuration Example 3 of Fig. 10, similar to Configuration Example 2, one state control valve 15 is shared by multiple supply units 11. In Configuration Example 3 of Fig. 10, a total of two state control valves 15A and 15B are used. One state control valve 15A is shared by each supply unit 11 corresponding to containers 5M and 5C. In addition, one state control valve 15B is shared by each supply unit 11 corresponding to containers 5Y and 5Bk.

[0073] The state control valve 15A is arranged upstream (toward the pressure adjustment unit 40) of the branch point between the pipe 19A and the pipe 19 of each supply unit 11 corresponding to the containers 5M and 5C. The state control valve 15B is arranged upstream (toward the pressure adjustment unit 40) of the branch point between the pipe 19A and the pipe 19 of each supply unit 11 corresponding to the containers 5Y and 5Bk. Such a configuration can also be adopted.

[0074] (Configuration Example 4) Fig. 11 shows another configuration example. In Configuration Example 4 of Fig. 11, similar to Configuration Examples 2 and 3, one state control valve 15 is shared by multiple supply units 11. In Configuration Example 4 of Fig. 11, a total of three state control valves 15A to 15C are used. One state control valve 15A is shared by each supply unit 11 corresponding to containers 5M and 5C. A unique state control valve 15B is provided in the supply unit 11 corresponding to container 5Y. A unique state control valve 15C is provided in the supply unit 11 corresponding to container 5Bk.

[0075] The state control valve 15A is arranged upstream (toward the pressure adjustment unit 40) of the branch point between the pipe 19A and the pipe 19 of each supply unit 11 corresponding to the containers 5M and 5C. The state control valve 15B is arranged downstream (toward the intermediate tank 20) ​​of the branch point between the pipe 19A and the pipe 19 of the supply unit 11 corresponding to the container 5Y. The state control valve 15C is arranged downstream (toward the intermediate tank 20) ​​of the branch point between the pipe 19A and the pipe 19 of the supply unit 11 corresponding to the container 5Bk. Such a configuration can also be adopted.

[0076] As in the above configuration examples 2 to 4, the recording apparatus 1 can be designed by selecting the number and arrangement of the state control valves 15 according to the type and characteristics of the ink used.

[0077] <Fourth embodiment> An example of the configuration of the state control valve 15 will be described with reference to Fig. 12. Fig. 12 is a diagram showing an example of the configuration of the state control valve 15 that uses a rotary cam. The example in Fig. 12 is an example of a configuration in which each of the pipes 19 of four supply units 11 is opened and closed by a single drive motor 205.

[0078] The state control valve 15 includes a pressing lever 201, a follower lever 202, and a rotating cam 203, each provided corresponding to one of the four pipes 19. The rotating cam 203 is driven by a drive motor 205 to close and open each of the pipes 19. The follower lever 202 is a rotating member whose one end is journaled and whose position changes depending on the phase of the journal cam 203. The pressing lever 201 is a rotating member whose one end is journaled and which presses the follower lever 202 via a lever biasing member 204. In this embodiment, the lever biasing member 204 is a coil spring, and is disposed between the other end of the follower lever 202 and the other end of the pressing lever 201.

[0079] The drive motor 205, the shaft of the rotating cam 203, and the shaft of the pressing lever 201 are connected by a drive transmission unit (not shown) such as a gear. A one-way clutch (not shown) that switches the drive between the rotating cam 203 and the pressing lever 201 is arranged midway through the drive transmission unit (not shown). In other words, when the drive motor 205 rotates forward, the drive is transmitted only to the rotating cam 203, and when it rotates reverse, the drive is transmitted only to the pressing lever 201. The four rotating cams 203 are arranged so that they are in different phases.

[0080] 13 shows the operation when the pipe 19 is closed. When the pipe 19 is closed, first, the drive motor 205 is driven in the forward direction to switch the phase of the rotary cam 203 to the low position. Then, the drive motor 205 is driven in the reverse direction to rotate the pressing lever 201 counterclockwise. By doing so, the pressing force of the pressing lever 201 acts on the follower lever 202 via the lever biasing member 204, and the follower lever 202 rotates clockwise. Therefore, the pipe 19 is closed at the end of the follower lever 202.

[0081] 14 shows the operation when the pipe 19 is not blocked. When the pipe 19 is not blocked, the phase of the rotating cam 203 is switched to the High position by driving the drive motor 205 in the forward direction. As a result, even if the pressing force of the pressing lever 201 acts on the follower lever 202, it abuts against the outer peripheral surface of the rotating cam 203, and the follower lever 202 does not rotate any further. In other words, the pipe 19 is not blocked.

[0082] By switching the phase of the rotary cam 203 through these operations, the four pipes 19 can be selectively opened or closed.

[0083] 15 shows another example of the configuration of the state control valve 15. Fig. 15 is a diagram showing an example of the configuration of the state control valve 15 using a translational cam. This example configuration has a translational cam 302 that is translationally driven by a drive motor (not shown), a follower lever 301 whose position changes due to the action of the translational cam 302, and a lever biasing member 303 that biases the follower lever 301. The follower lever 301 and the lever biasing member 303 are provided corresponding to the four pipes 19, respectively.

[0084] Fig. 16 is an explanatory diagram of the operation of the configuration example in Fig. 15. When the pipe 19 is to be blocked, the translational cam 302 is driven by the drive motor, and the follower portion 301a of the follower lever 301 is moved away from the cam portion 302a of the translational cam 302. As a result, the follower lever 301 is rotated counterclockwise by the biasing force of the lever biasing member 303, and the blocking portion 301b of the follower lever 301 blocks the pipe 19.

[0085] When the pipes 19 are not to be blocked, the translational cam 302 is driven so that the follower portion 301a of the follower lever 301 abuts against the cam portion 302a. This causes the follower lever 301 to rotate clockwise, and the blocking portion 301b moves away from the pipes 19, thereby unblocking the pipes 19. By switching the phase of the translational cam 302, the four pipes 19 can be selectively opened or closed.

[0086] Fifth Embodiment In the first embodiment, the pressure adjustment unit 40 is configured from the exhaust unit 41 and the atmosphere vent unit 42, but a supply unit that supplies air to the pressure chamber 23 may be used instead of the atmosphere vent unit 42. The supply unit has a pump that pressurizes the pressure chamber 23, and this displaces the wall 24 in a direction that reduces the size of the liquid chamber 22, thereby supplying the liquid. In this configuration, the biasing member 25 is not necessary. The exhaust unit 41 and the supply unit may share a pump, and the flow direction of the exhaust and supply of air may be switched by a valve.

[0087] The buffer tank 30 may be mounted on the carriage 2 or may be fixedly disposed at a location separate from the carriage 2 .

[0088] The present disclosure can also be realized by a process in which a program that realizes one or more functions of the above-described embodiments is supplied to a system or device via a network or a storage medium, and one or more processors in a computer of the system or device read and execute the program. The present disclosure can also be realized by a circuit (e.g., an ASIC) that realizes one or more functions.

[0089] The technical ideas derived from this disclosure are not limited to the disclosed exemplary embodiments, but are intended to encompass various modifications to the exemplary embodiments, or the replacement of equivalent structures or functions, etc. The scope of the following claims should be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

[0090] This application claims priority based on Japanese Patent Application No. 2024-112650, filed July 12, 2024, the entire contents of which are incorporated herein by reference.

Claims

1. A recording device comprising: a liquid chamber into which liquid is introduced from a liquid container and which contains liquid to be supplied to an ejection means which ejects the liquid onto a recording medium; forming means which forms a pressure chamber adjacent to the liquid chamber; a wall which separates the liquid chamber from the pressure chamber and which changes the volume of the liquid chamber by displacing according to the pressure of the pressure chamber; pressure adjustment means which communicates with the pressure chamber via a communication passage and which is able to switch between introducing liquid into the liquid chamber and supplying liquid to the ejection means by adjusting the pressure of the pressure chamber; and a valve provided in the communication passage, wherein the valve communicates between the pressure adjustment means and the pressure chamber in an open state, and blocks communication between the pressure adjustment means and the pressure chamber in a closed state, maintaining the pressure state of the pressure chamber.

2. A recording device according to claim 1, wherein, after liquid is introduced into the liquid chamber by adjusting the pressure in the pressure chamber to a negative pressure with the valve in an open state using the pressure adjusting means, a first operation is executed in which the valve is maintained in a closed state until a condition for starting the supply of liquid is met.

3. A recording device according to claim 2, wherein a second operation is selectively performed in conjunction with the first operation, and in the second operation, when the supply start condition is met, the valve is in an open state and the pressure in the pressure chamber is adjusted to a negative pressure by the pressure adjustment means, thereby introducing liquid into the liquid chamber, and then the pressure in the pressure chamber is adjusted to atmospheric pressure by the pressure adjustment means.

4. A recording device according to claim 2, comprising: a buffer tank disposed between the liquid chamber and the ejection means, for storing liquid to be supplied to the ejection means; and detection means for detecting the remaining amount of liquid in the buffer tank, wherein the supply start condition is a condition based on the detection result of the detection means.

5. A recording device according to claim 1, comprising: a first backflow prevention valve provided in a flow path upstream of the liquid chamber in the direction of liquid introduction, for preventing backflow of the liquid; and a second backflow prevention valve provided in a flow path downstream of the liquid chamber in the direction of liquid supply, for preventing backflow of the liquid.

6. A recording device according to claim 1, comprising biasing means for biasing the wall in a direction that reduces the volume of the liquid chamber, and the pressure adjusting means comprising: exhaust means for exhausting air from the pressure chamber through the communication passage; and atmosphere opening means for opening the pressure chamber to the atmosphere through the communication passage.

7. A recording device according to claim 1, comprising: second forming means for forming a second liquid chamber that receives liquid from a second liquid container and stores liquid to be supplied to second ejection means that ejects the liquid onto a recording medium, and a second pressure chamber adjacent to the second liquid chamber; and a second wall that separates the second liquid chamber from the second pressure chamber and changes the volume of the second liquid chamber by displacing in accordance with the pressure of the second pressure chamber; the communication passages having: a common communication passage connected to the pressure adjustment means; a first communication passage that branches off from the common communication passage and is connected to the pressure chamber; and a second communication passage that branches off from the common communication passage and is connected to the second pressure chamber; the pressure adjustment means communicates with the second pressure chamber via the second communication passage and is able to switch between introducing liquid into the liquid chamber and supplying liquid to the ejection means by adjusting the pressure of the second pressure chamber; the valve is provided in the first communication passage; and a second valve is provided in the second communication passage; a pressure adjusting means for adjusting the pressure of the second pressure chamber in an open state, and a pressure adjusting means for adjusting the pressure of the second pressure chamber in a closed state, thereby maintaining the pressure state of the second pressure chamber.

8. A recording device according to claim 1, comprising: second forming means for forming a second liquid chamber that receives liquid from a second liquid container and stores the liquid to be supplied to second ejection means that ejects the liquid onto a recording medium, and a second pressure chamber adjacent to the second liquid chamber; and a second wall that separates the second liquid chamber from the second pressure chamber and changes the volume of the second liquid chamber by displacing in accordance with the pressure of the second pressure chamber; the communication paths include a common communication path connected to the pressure adjustment means, a first communication path that branches off from the common communication path and is connected to the pressure chamber, and a second communication path that branches off from the common communication path and is connected to the second pressure chamber; the pressure adjustment means communicates with the second pressure chamber via the second communication path, and is able to switch between introducing liquid into the liquid chamber and supplying liquid to the ejection means by adjusting the pressure of the second pressure chamber; the valve is provided in the common communication path, and in an open state, communicates between the pressure adjustment means and the pressure chamber and the second pressure chamber, and in a closed state, blocks communication between the pressure adjustment means and the pressure chamber and the second pressure chamber, thereby maintaining the pressure states of the pressure chamber and the second pressure chamber.

9. A control method for a recording device comprising: forming means for forming a liquid chamber into which liquid is introduced from a liquid container and which stores liquid to be supplied to a discharge means which discharges the liquid onto a recording medium, and a pressure chamber adjacent to the liquid chamber; a wall which separates the liquid chamber from the pressure chamber and which changes the volume of the liquid chamber by displacing according to the pressure of the pressure chamber; pressure adjustment means which communicates with the pressure chamber via a communication path and adjusts the pressure of the pressure chamber; and a valve which is provided in the communication path and switches between communication on and off between the pressure adjustment means and the pressure chamber, the control method comprising the steps of: adjusting the pressure of the pressure chamber with the valve in an open state so that liquid is introduced into the liquid chamber by the pressure adjustment means; closing the valve after liquid has been introduced into the liquid chamber and maintaining the pressure state of the pressure chamber; and opening the valve and adjusting the pressure of the pressure chamber with the pressure adjustment means so that liquid is supplied from the liquid chamber to the discharge means.

10. A storage medium storing a program for causing a computer to execute the control method according to claim 9.

11. A program that causes a computer to execute the control method according to claim 9.

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