Printing apparatus and method for controlling a printing apparatus

Abstract

This recording device includes: a suction device for drawing liquid from a nozzle; a valve located at a first position in the supply path and switchable between an open state where the supply path is connected to the valve and a closed state where the supply path is closed; and a control device for: controlling a first suction, wherein the suction device performs suction while the valve is open, such that the liquid reaches the first position or a second position downstream of the first position; controlling a second suction, wherein the suction device performs suction after the first suction while the valve is closed; and controlling the valve to open after the second suction.

Description

Technical Field

[0001] The technology disclosed herein relates to a printing device and a method for controlling the printing device. Background Technology

[0002] There exists a printer in which a choke mechanism is arranged for a supply tube that supplies ink to an ejector head. Patent Document 1 describes a choke suction method in which a high negative pressure is generated by suction from the nozzle surface of the ejector head while the choke mechanism is closed, and then the choke mechanism is set to an open state to rapidly increase the ink supply pressure.

[0003] Reference List

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2006-110822 Summary of the Invention

[0006] Technical issues

[0007] As a method of blocking the ink flow path to perform choke suction, it is conceivable to flatten the tube forming the ink flow path from the outer diameter side and bring the portions on the inner diameter side into close contact with each other. When the tube is released from flattening, the inner diameter portions of the blocked parts separate from each other due to the tube's self-restoring force. This allows the flow path to return from a blocked state to a connected state. However, even when the inner diameter portions of the tube are in close contact in a dry state, they may in some cases adhere to each other. When the inner diameter portions of the tube adhere to each other, there is a possibility that the flow path may not return from a blocked state to a connected state, potentially causing problems.

[0008] The present disclosure has been made in view of the aforementioned problems, and its purpose is to suppress the occurrence of problems in suction.

[0009] Problem Solution

[0010] A printing apparatus according to the present disclosure includes: a canister configured to contain liquid to be supplied to a printhead, the printhead ejecting the liquid from an ejection port; a supply passage configured to supply liquid from the canister to the printhead; a suction unit configured to suction liquid from the ejection port; a valve disposed at a first position in the supply passage and configured to switch between an open state in which the supply passage is connected and a closed state in which the supply passage is blocked; and a control unit configured to control the valve and the suction unit, wherein the control unit: performs control of a first suction, wherein the valve is set to an open state and the suction unit performs suction such that liquid reaches the first position or a second position downstream of the first position; after the first suction, performs control of a second suction, wherein the valve is set to a closed state and the suction unit performs suction; and after the second suction, performs control to set the valve to an open state.

[0011] According to the technology disclosed herein, problems with suction can be suppressed.

[0012] Further features of the technology disclosed will become apparent from the following description of embodiments with reference to the accompanying drawings. Attached Figure Description

[0013] [ Figure 1 ] Figure 1 This is a perspective view showing the printing device with its cover component open.

[0014] [ Figure 2 ] Figure 2 This is a schematic diagram of the ink supply chain.

[0015] [ Figure 3 ] Figure 3 This is a schematic diagram showing the positional relationship between the ink can and the printhead.

[0016] [ Figure 4 ] Figure 4 This is a perspective view of a choke valve.

[0017] [ Figure 5 ] Figure 5 This is a schematic cross-sectional view of a choke valve.

[0018] [ Figure 6 ] Figure 6 It is a schematic cross-sectional view of the recovery unit.

[0019] [ Figure 7 ] Figure 7 This is a schematic diagram of the printhead and suction cap.

[0020] [ Figure 8 ] Figure 8 This is a schematic diagram of a suction pump.

[0021] [ Figure 9 ] Figure 9 This is a diagram illustrating an example of the hardware configuration of a printing device.

[0022] [ Figure 10 ] Figure 10 This is a flowchart illustrating an example of the processing in an ink filling operation.

[0023] [ Figure 11 ] Figure 11 This is a flowchart of choke blocking and choke opening processes.

[0024] [ Figure 12 ] Figure 12 This is a schematic diagram of the ink supply chain.

[0025] [ Figure 13 ] Figure 13 This is a schematic diagram of the ink supply chain.

[0026] [ Figure 14 ] Figure 14 This is a flowchart illustrating an example of the processing in an ink filling operation. Detailed Implementation

[0027] Embodiments of the technology disclosed herein are described below with reference to the accompanying drawings. The following embodiments do not limit the scope of the technology according to the claims. Although several features are described in the following embodiments, not all of these features are essential to the technology of this disclosure, and the features can be used in any combination. It should be noted that the same or similar configurations are described by using the same reference numerals, and in some cases, repeated descriptions are omitted.

[0028] In this specification, “printing” (also referred to in some cases as “character printing” or “printing”) is not limited to the formation of meaningful information (such as characters and graphics), the information to be formed may be meaningful or meaningless. It is assumed that “printing” broadly refers to the formation of images, designs, patterns, etc. on a printing medium or the handling of a printing medium, regardless of whether the object formed or handled is obviously visually significant to a human.

[0029] Furthermore, "printing media (sheets)" not only broadly includes printing paper used in general imaging equipment, but also broadly includes transportable media such as cloth, plastic film (OHP), metal sheets, glass, ceramics, wood, and leather.

[0030] Furthermore, "ink" (in some cases referred to as "liquid") will be interpreted broadly, as in the definition of "printing" above. It is assumed that "ink" refers to a liquid that can be used to form images, designs, patterns, etc., by being applied to a printing medium, to process the printing medium, or to process the ink (e.g., to cure or prevent the color material in the ink applied to the printing medium from dissolving).

[0031] <First Embodiment>

[0032] [General configuration of printing equipment]

[0033] Figure 1 This is a perspective view of the inkjet printing apparatus 1 (hereinafter referred to as printing apparatus 1) according to this embodiment. Figure 1 part (a) and Figure 1 Part (b) shows the open state of the cover member 112, which will be described later, to clearly illustrate the internal configuration. In this embodiment, the cover member 112 is configured to function as a scanner unit with an ADF. The printing device 1 includes: a printhead 14 that ejects ink as a liquid onto a printing medium; and an ink reservoir 17 that holds the ink to be supplied to the printhead 14. Furthermore, the printing device 1 includes a supply tube 15 that forms an ink supply passage for supplying ink from the ink reservoir 17 to the printhead 14. In this embodiment, in some cases, supply tubes 151 to 154 will correspond to various ink colors (see reference) that will be described later. Figure 2 This is collectively referred to as the supply pipe 15. Furthermore, the printing apparatus 1 includes a carriage 13 on which the print head 14 is detachably mounted and reciprocates. It should be noted that the print head 14 can be fixed to the carriage 13.

[0034] The printing apparatus 1 includes a plurality of rollers 23 (some not shown) as a transport unit for feeding sheet-like printing media 19. The plurality of rollers 23 transport the printing media 19 along a transport direction (Y direction in the figure) orthogonal to the main scanning direction (X direction in the figure), which is the direction of movement of the carriage 13 (printhead 14). Furthermore, a platform 22 supporting the printing media 19 is provided. Figure 1 In part (b), the printhead 14 moves below the range to face the printhead 14. Figure 1 Part (a) shows the carriage 13 moving above the platform 22, and Figure 1 Part (b) is where the carriage 13 is located on the suction cap 211, which will be described later (see reference). Figure 6 The state above.

[0035] The carriage 13 is equipped with a pivotally supported, rotatable disassembly unit 143. The user can disassemble the printhead 14 from the carriage 13 by operating the disassembly unit 143. Furthermore, the housing 11 is configured to completely cover these internal components. With the cover member 112 open, the carriage 13, printhead 14, stage 22, supply pipe 15, and the choke valve operating unit 161 (described later) are all visible. Figure 4 They are in a state where they are at least partially exposed. The choke valve 16 is a valve that switches the ink supply passage formed by the supply pipe 15 between a blocked state and an open state. Details will be described later.

[0036] The print media width 191 indicates the width of the print media 19 having the maximum printable size of the printing device 1 of this embodiment. The direction in which the print media width 191 extends (width direction) is orthogonal to the transport direction of the transport unit to the print media 19.

[0037] Furthermore, the printing device 1 includes a cover sensor 18 that can detect the state of the cover member 112. For example, the cover sensor 18 can detect the open and closed states of the cover member 112. Specifically, a protrusion (not shown) is provided on the inner side (back side) of the cover member 112, and the cover sensor 18 detects that the cover member 112 is in the closed state when the protrusion contacts the cover sensor 18, and detects that the cover member 112 is in the open state when the protrusion does not contact the cover sensor 18. In addition, an ink tank cap 179 is arranged in the upper portion of the ink tank 17 to cover the ink filling port 176 (see...). Figure 2 ) and inkwell cap 177 (see Figure 2 It can be opened and closed by rotating it.

[0038] Figure 2 This is a diagram showing an overview of the ink tank 17, printhead 14, and supply tube 15 connecting the ink tank 17 and printhead 14. Next, the configuration of the ink tank 17 and supply tube 15 will be described. The printing device 1 includes a plurality of ink tanks 17, each for a corresponding ink color. In this embodiment, four ink tanks 17 are provided: a black ink tank 171, a cyan ink tank 172, a magenta ink tank 173, and a yellow ink tank 174. In this embodiment, the black ink tank 171 is disposed on one side of the printing device 1 in the width direction, and the cyan ink tank 172, magenta ink tank 173, and yellow ink tank 174 are disposed side-by-side on the other side. Specifically, as... Figure 1 As shown, the ink cartridges are configured such that the printed medium 19, after printing, passes through the space between the black ink cartridge 171 and the color ink cartridge groups 172 to 174. Furthermore, ink cartridge 17 is a general term for ink cartridges of corresponding ink colors, and it is assumed that each ink cartridge 171 to 174 of a corresponding ink color has the configuration of ink cartridge 17 described below.

[0039] Each of the supply tubes 15 for supplying corresponding ink to the printhead 14 is attached to the corresponding ink reservoir 17. In this embodiment, the supply tube 15 is a supply passage forming member that forms an ink supply passage for supplying ink from the ink reservoir 17 to the printhead 14. In this embodiment, the tube forming the supply tube 15 is made of a flexible material such as rubber or an elastomer and is bendable as the printhead 14 moves. Furthermore, the ink supply passage can be blocked by flattening a portion of the supply tube 15 with a choke valve 16, which will be described later. Supply tube 15 is a collective term for the supply tubes 151 to 154 of the corresponding ink colors, which will be described later, and it is assumed that each of the supply tubes 151 to 154 of the corresponding ink colors has the configuration of the supply tube 15 described below.

[0040] Each ink can 17 is attached to an atmospheric connection tube 178 that allows the interior of the ink can 17 to communicate with the atmosphere. Furthermore, an ink filling port (filling section) 176 for filling ink is provided in the upper part of the ink can 17. Additionally, an ink can cap 177 for sealing the ink filling port 176 is attached to the ink filling port 176. The user can fill the ink can 17 with ink through the ink filling port 176 by removing the ink can cap 177.

[0041] Furthermore, the supply pipe 15 and the atmospheric connection pipe 178 are equipped with ink tank valves 180 that block the communication between ink and air. In this embodiment, the ink tank valves 180 are respectively located on the black side and the color side.

[0042] When the ink can valve 180 on the black side is closed, the connection between each ink supply passage in the ink supply path formed by the supply pipe 15 connected to the black ink can 171 and the flow passage in the atmospheric connection pipe 178 is blocked. When the ink can valve 180 on the color side is closed, the flow passage between the ink supply path formed by the supply pipes 15 connected to the cyan ink can 172, magenta ink can 173, and yellow ink can 174 respectively and the flow passage in the atmospheric connection pipe 178 is blocked.

[0043] Figure 3This is a schematic diagram showing the positional relationship between the ink tank 17, the printhead 14, and the ink ejection port (also simply referred to as nozzle) 142 of the printhead 14. In the printing apparatus 1, an air-liquid exchange unit 175, which performs the exchange of air with ink in the ink tank 17, is located at a height H in the vertical direction below the ink ejection port 142 of the printhead 14 to prevent ink leakage from the ink ejection port 142 of the printhead 14. Specifically, this configuration allows a negative pressure generated by the head difference corresponding to the height H to be applied to the ink ejection port 142. The air-liquid exchange unit 175 is formed with an open area that maintains the meniscus of the ink. Furthermore, a buffer chamber 17a is provided in the lower portion of the ink tank 17. The buffer chamber 17a can accommodate ink that disrupts the meniscus in the air-liquid exchange unit 175, and is pushed out when the air in the ink receiving chamber 17b containing ink expands due to changes in air pressure, temperature, etc. This prevents ink from leaking from the ink tank 17 through the atmospheric communication pipe 178.

[0044] It should be noted that the internal volume of the buffer chamber 17a is set such that, under normal operating conditions, ink does not reach the atmospheric end portion of the atmospheric connection pipe 178 on the atmospheric side. In this embodiment, the gas-liquid separation membrane 178a is disposed in the atmospheric end portion of the atmospheric connection pipe 178 on the atmospheric side to allow air to pass through while blocking ink from the can side and preventing ink leakage to the outside. Various commercially available materials can be used as the material for the gas-liquid separation membrane.

[0045] Furthermore, the connector portion 182 is a component that connects the flow passages of the supply tube 15 and the printhead 14 to each other, and is configured to be detachable from the printhead 14. When the user operates the disassembly operation unit 143 in the opening direction to remove the printhead 14 from the carriage 13, the connector portion 182 disengages from the printhead 14. This disconnects the supply tube 15 from the printhead 14. Conversely, when the user mounts the printhead 14 onto the carriage 13, the user performs a closing operation on the disassembly operation unit 143 to establish a connector connection between the connector portion 182 and the printhead 14. This connector connection again establishes communication between the flow passages of the supply tube 15 and the printhead 14, allowing ink to be supplied to the printhead 14.

[0046] Next, by using Figure 1 , Figure 2 and Figure 3 This section describes the configuration of the ink supply system according to this embodiment and the process up to the point when printing (recording) becomes possible. During ink filling, the user opens the ink can cap 179, removes the ink can lid 177, and fills the ink can 17 with ink from an ink bottle or the like through the ink filling port 176. In this situation, the ink can valve 180 closes along with the opening of the ink can cap 179, and the flow paths in the ink supply passage 155 and the atmospheric connection pipe 178 are blocked.

[0047] With ink filling complete, the user seals the ink filling port 176 with the ink can cap 177 and closes the ink can lid 179. In this case, when the ink can lid 179 is closed, the ink can valve 180 does not operate along with the ink can lid 179 and remains in the closed state. Closing the lid member 112 switches the ink can valve 180 from the closed state to the open state, and connects the flow path of the ink supply passage 155 and the atmospheric connection pipe 178. When the ink can cap 177 is removed and the ink filling port 176 opens to the atmosphere, the ink can valve 180 blocks the flow path of the ink supply passage 155 and the atmospheric connection pipe 178.

[0048] After the ink filling is detected to be complete, in printing device 1, suction cap 211 (see...) Figure 6 The ink supply tube 15 is pressed against the ejection nozzle surface of the printhead 14, and an ink suction operation, including the initial filling which will be described later, can be performed. Through this suction operation, the interior of the supply tube 15 and the interior of the printhead 14 are filled with ink. It should be noted that the detection of ink filling completion is performed by detecting the closure of the cover member 112 using the cover sensor 18. Alternatively, a remaining ink detection unit can be provided to detect the remaining ink level in the ink tank 17, and ink filling completion can be detected by having the remaining ink detection unit detect the filling of a predetermined amount or more of ink. In the case where the printing device 1 does not include such a detection unit, a configuration can also be adopted where the user inputs "ink filling completion" into the printing device 1 after ink filling is complete. When ink is ejected from the ink ejection nozzle 142 of the ink-filled printhead 14 during the printing operation, the negative pressure in the printhead 14 increases by an amount corresponding to the reduction in ink, and ink is supplied from the ink tank 17 to the printhead 14. Thus, ink is continuously supplied from the ink tank 17 to the printhead 14 until the ink in the ink tank 17 reaches a predetermined amount or drops below a predetermined amount.

[0049] [About choke valves]

[0050] Next, the configuration of the choke valve 16, which serves as the on / off valve mechanism for the ink supply path in this embodiment, will be described. First, using... Figure 1 and Figure 2 The configuration of the choke valve 16 according to this embodiment is described. The choke valve 16 is disposed between the printhead 14 and the ink tank valve 180 of the supply pipe 15. The choke valve 16 is used to switch between an open state in which the ink tank 17 and the printhead 14 are connected to each other and a closed state in which the ink tank 17 and the printhead 14 are not connected to each other. When the choke valve 16 is closed, the connection of the ink supply passage 155 formed by the black supply pipe 151, the cyan supply pipe 152, the magenta supply pipe 153, and the yellow supply pipe 154 is completely blocked.

[0051] The choke valve 16 can be manually switched from a state where the ink supply passage 155 is connected (open state) to a state where the ink supply passage 155 is blocked (closed state) by the user, and includes an operating unit 161 for manual operation by the user (see...). Figure 4 The choke valve 16 is configured to be switched between an open and a closed state via an operating unit 161. The operating unit 161 of the choke valve 16 is arranged in the area covered by the cover member 112, and this area is through which the conveyed printing medium 19 passes.

[0052] The choke valve 16 is configured to switch the ink supply passage 155 between an open and closed state, in addition to being manually operated by the user. The choke valve drive unit 169 is controlled by the CPU 201 (see [link to control unit]). Figure 9 The choke valve drive unit 169 is controlled by an electric motor 1691, which drives the operating unit 161 in a manner similar to user operation. Figure 2 ), reduction gear system 1692 (see Figure 2 As described above, the choke valve drive unit 169 is configured to allow both control unit drive and user manual operation. Furthermore, in Figure 1 The location indicated by Ib-1 in part (b) is provided with a printing mark 166 and a maintenance mark 167. Figure 1 The (b-1) part is an enlarged view of Ib-1.

[0053] Figure 4 This is a perspective view showing an overview of the choke valve 16 according to this embodiment. Figure 4 Part (a) is the operation unit 161 in which... Figure 4 This is a view of the case indicated by the print mark 166 shown in section (a-1). When the operating unit 161 is on the side indicated by the print mark 166, the choke valve 16 does not block the ink supply passage 155, and the printing device 1 is in a state where ink can be supplied from the ink tank 17 to the print head 14. Therefore, the printing device 1 is in a state where it can perform printing on the printing medium 19.

[0054] at the same time, Figure 4 Part (b) is the operation unit 161 in which... Figure 4The illustration shows the case where maintenance mark 167 is indicated on the side shown in section (b-1). When the operating unit 161 is on the side indicated by maintenance mark 167, the choke valve 16 blocks the ink supply passage 155, and no ink is supplied from the ink tank 17 to the printhead 14. Therefore, the user can perform printhead 14 replacement operations, transportation, etc., while the movement of ink in the ink supply passage 155 is suppressed. Furthermore, print mark 166 and maintenance mark 167 allow the user to visually identify the status of the choke valve 16.

[0055] Figure 5 This is a cross-sectional view illustrating an overview of the choke valve 16 according to this embodiment. Figure 5 Part (a) is a cross-sectional view of the operating unit 161 on the side indicated by the printed mark 166. Figure 5 Part (b) is a cross-sectional view of the operating unit 161 on the side indicated by maintenance mark 167.

[0056] like Figure 5 As shown, the choke valve 16 includes an operating unit 161, a holding unit 162, a receiving member 163, a displacement member 164, a cam 165, and a choke valve drive unit 169 connected to the operating unit 161. The choke valve drive unit 169 is configured to drive the choke valve 16 via the operating unit 161. Furthermore, the operating unit 161 is configured to allow both manual operation and operation by the choke valve drive unit 169. Specifically, this is achieved by providing a backlash (so-called mechanical timer) corresponding to manual operation in the rotational direction in the connection portion between the choke valve drive unit 169 and the operating unit 161. This configuration is not limited to the above configuration and can also be adopted, for example, by temporarily disconnecting the connection with the choke valve drive unit 169 using a clutch mechanism.

[0057] The holding unit 162 holds the supply tube 15. One end of the supply tube 15 is connected to the printhead 14, and the other end is connected to the ink reservoir 17. The supply tube 15 includes a curved region that can bend as the printhead 14 moves. A choke valve 16 is arranged such that the curved region in the supply tube 15 is located between the printhead 14 and the holding unit 162. Specifically, the choke valve 16 is arranged in the region of the supply tube 15 that does not move with the carriage 13. Furthermore, as... Figure 2 As shown, the supply tube 15 is fixed by a first fixing portion 184 on the printhead 14 side and a second fixing portion 183 on the ink tank 17 side. In this embodiment, the holding unit 162 also serves as the second fixing portion 183.

[0058] The displacement member 164 is a member that can be displaced in the direction in which it interferes with the supply pipe 15. Specifically, the displacement member 164 is configured to rotate in either a blocking or opening direction while rotating about its axis of rotation toward the supply pipe 15. Furthermore, the receiving member 163 is a member for receiving the displacement member 164 displaced in the direction in which it interferes with the supply pipe 15. The receiving member 163 is located on the side of the supply pipe 15 opposite to the side where the displacement member 164 is located. The displacement member 164 flattens the supply pipe 15 while pressing it against the receiving member 163, thereby blocking the ink supply passage 155. Specifically, it is assumed that the choke valve of this embodiment is described using a so-called pinch valve method.

[0059] The receiving member 163 is independently formed as a movable member biased by a biasing member having a load sufficient to block the pipe for the corresponding pipe. This movable configuration on the receiving member 163 side allows for the management of appropriate pressing pressure to accommodate variations in outer diameter and thickness in multiple pipes, even when the displacement member 164 is a single piece. Therefore, the reliability of the blocking and opening operation of the choke valve 16 is improved.

[0060] The cam 165 contacts the displacement member 164, and causes the displacement member 164 to move along... Figure 5 The displacement is essentially downward (-Z direction). In this embodiment, the cam 165 rotates integrally with the operating unit 161, and the cam surface 1651 contacts the displacement member 164. When the operating unit 161 is operated by the user or driven by the choke valve drive unit 169, the cam 165 rotates with the operation or drive. Then, the displacement member 164, pressed by the cam surface 1651, moves along... Figure 5 The ink supply passage 155 is blocked as a result of the displacement in the basically downward direction (-Z direction).

[0061] When the ink supply passage 155 is to return from a blocked state to a connected state, the cam surface 1651 rotates in the direction in which the pressure of the displacement member 164 is released and the displacement member 164 gradually moves away. Then, from the flattened supply tube 15 and along Figure 5 The reaction force received by the biasing member 1641 of the basically upward (+Z direction) biasing displacement member 164 causes the displacement member 164 to follow the cam surface 1651 and retract upward. As described above, the operation unit 161 can switch between the state of the choke valve 16 blocking the supply pipe 15 and the state of the supply pipe 15 being open.

[0062] Figure 4 part (a) and Figure 5Part (a) shows the state where the displacement member 164 is not flattening the supply tube 15 and the ink supply passage 155 is in a connected state. At this time, the operating unit 161 is located on the side indicated by the printing mark 166. In this state, as... Figure 5 As shown in section (a-1), ink in supply tube 15 can be supplied from ink tank 17 to printhead 14 via ink supply passage 155. In... Figure 4 As shown in section (b), when the operating unit 161 is rotated in this state toward the side indicated by the maintenance mark 167, the cam surface 1651 of the cam 165, which rotates integrally with the choke valve 16 as described above, also rotates. Then, the cam surface 1651 causes the displacement member 164 to be displaced in the direction in which the displacement member 164 interferes with the supply pipe 15.

[0063] Figure 4 Part (b) and Figure 5 Part (b) shows the state where the displacement member 164 is flattening the supply tube 15 and the ink supply passage 155 is blocked. Figure 5 As shown in section (b-1), the supply tube 15 is flattened between the displacement member 164 and the receiving member 163, and the ink supply passage 155 of the supply tube 15 is blocked. In this case, the supply tube 15 is in a state where ink in the ink tank 17 cannot be supplied to the print head 14. Although the case where the choke valve 16 is manually operated by the user is sometimes described in this embodiment, the operation is the same when it is driven by the choke valve drive unit 169. When the choke valve drive unit 169 is driven by the CPU 201, the user does not need to open the cover member 112 to operate the operation unit 161.

[0064] Furthermore, in this embodiment, closing the choke valve 16 simultaneously blocks the ink supply passages 155 of all ink color supply pipes 15. However, it is possible to adopt a configuration where multiple choke valves 16 are provided for the corresponding supply pipes 15 of the corresponding ink color, and each ink supply passage 155 can be blocked individually. Additionally, the choke valves 16 can be individually provided on the black side and the color side, respectively.

[0065] The operation unit 161 is located where it is covered by the housing 11 and the cover member 112. Specifically, the operation unit 161 is configured to be exposed when the cover member 112 is open. When the cover sensor 18 detects that the cover member 112 is open, the printing device 1 is controlled to not perform a printing operation through the print head 14. By placing the operation unit 161 inside the cover member 112, the possibility of the user accidentally operating the operation unit 161 during printing operations or other activities of the printing device 1 can be suppressed.

[0066] Furthermore, in this embodiment, since a cover sensor 18 is provided, the printing device 1 can detect whether the printing device 1 is in a state where the user-operable operation unit 161 is accessible by using the cover sensor 18. The cover sensor 18 is not limited to a mechanical sensor that detects mechanical contact, but can also be, for example, an optical sensor.

[0067] In addition, such as Figure 4 As shown, the choke valve 16 is equipped with a choke valve sensor 168 that detects the open and closed states of the choke valve 16. It is assumed that the choke valve sensor 168 in this embodiment is an optical sensor. When the operating unit 161 rotates, the displacement member 164 is pressed by the cam 165, and a mark 164a provided in the displacement member 164 obscures or opens the optical axis center of the choke valve sensor 168. Thus, the choke valve sensor 168 detects whether the choke valve 16 is in the open or closed state. It should be noted that a switch using mechanical contacts or other well-known configurations can be used in the choke valve sensor 168.

[0068] [About the recovery unit]

[0069] Figure 6 This is a perspective view showing an overview of the recovery unit 21. In this embodiment, the printing device 1 includes a recovery unit 21 for maintaining or restoring the ejection performance (printing performance) of the printhead 14. In this embodiment, the recovery unit 21 is disposed inside the main body of the printing device 1 covered by the housing 11. The recovery unit 21 includes a suction cap 211 covering the printhead 14 and a suction mechanism 212 for suctioning ink from the suction cap 211. The suction mechanism 212 includes a suction tube 213 connected to the suction cap 211 and a suction pump 214 for suctioning ink from the suction cap 211 via the suction tube 213. In this case, the suction tube 213 is an ink suction passage 2131 forming for suctioning ink from the suction cap 211 (see reference). Figure 7 The suction passage forming component is as follows: In addition, in this embodiment, the suction tube 213 is formed from a flexible component such as rubber or an elastomer, similar to the supply tube 15.

[0070] In addition, the recovery unit 21 includes a wiper 221 for wiping the nozzle surface of the ink jet nozzle 142, a holding member (not shown) for holding the wiper 221, and an ink removal member (not shown) for removing ink adhering to the wiper 221.

[0071] Figure 7 This is a schematic diagram showing the print head 14 and the suction cap 211. Figure 7 In the middle, the supply tube 15 is connected to the right surface portion of the printhead 14. Furthermore, the suction cap 211 is configured to be accessible via the cap drive unit 217 (see...). Figure 9The printhead 14 advances towards and retracts from the ink ejection port 142, and can cover the ejection port surface where the ink ejection port 142 is located from below. The interior of the printhead 14 is not completely filled with ink, and an air layer 144 is always present. Note that the suction cap 211 is located at a predetermined position in the printing device 1, and during the suction operation, the printhead 14 is moved by the carriage 13 to a return position located above the suction cap 211.

[0072] A sub-canister 146 is disposed inside the printhead 14, in which ink supplied from the supply tube 15 via the connector portion 182 accumulates. A flow passage 6 communicating with the inkjet nozzle 142 is disposed below the sub-canister 146, with a filter 145 disposed between the flow passage 6 and the sub-canister 146. The placement of the sub-canister 146 within the printhead 14 allows for a relatively large supply of ink over short periods, and is therefore a suitable configuration for, for example, high-speed printing.

[0073] Filter 145 is configured to prevent solid objects (such as foreign matter) in the supplied ink from entering the ink ejector 142 side, while allowing ink to pass through. Filter 145 is a sheet-like member with a fine mesh for trapping foreign matter, and it is assumed that filter 145 in this embodiment is formed of a mesh member made of corrosion-resistant stainless steel. Alternatively, various members such as mesh members made of other metals and nonwoven fabrics made of resin can be used as members forming filter 145, to the extent that the purpose of filtering can be achieved.

[0074] Figure 8 This is a cross-sectional view showing an overview of the suction pump 214. (Usage) Figure 8 The following describes the suction operation of the suction mechanism 212 on the ink within the suction cap 211. In this embodiment, the suction mechanism 212 includes two suction tubes 213 for black and color ink.

[0075] The suction pump 214 includes a roller 215 and a pump drive unit 216, which includes an electric motor and is driven to rotate (see [link]). Figure 9 The pump 214 also includes a rotating member 219 that rotates with the pump drive unit 216. The suction pump 214 also includes a roller drive member 218 configured to project outwardly in the radial direction from the rotating member 219.

[0076] Roller 215 is configured to rotate about the axis of rotation of rotating member 219. While rotating member 219 rotates, roller drive member 218 rotates about the axis of rotating member 219. Then, with roller drive member 218 in contact with roller 215 and rotating about the axis of rotating member 219, roller 215 rotates about the axis of rotating member 219. Then, with roller 215 rotating about rotating member 219 and squeezing suction tube 213 while ink ejection nozzle 142 is covered by suction cap 211, negative pressure is generated inside suction cap 211, thereby performing suction by suction mechanism 212.

[0077] In this embodiment, two suction tubes 213 are arranged side by side in the vertical direction, with a rotating member 219 arranged between the suction tubes 213. Furthermore, in this embodiment, three rollers 215 are provided, and the three rollers 215 rotate sequentially and squeeze the two suction tubes 213 to simultaneously perform suction from both suction tubes 213.

[0078] In addition, one end of each suction tube 213 is connected to a waste liquid tank (not shown), and the ink drawn by the suction pump 214 is discharged into the waste liquid tank via the suction tube 213.

[0079] Furthermore, in this embodiment, while the roller 215 is flattening the suction tube 213, the suction pump 214 can be stopped by stopping the pump drive unit 216 (see [link]). Figure 9 The suction pump 214 is driven to block the ink suction passage 2131. Specifically, in this embodiment, the suction pump 214 can also be said to act as a blocking valve for the ink suction passage 2131. Since the suction pump 214 included in the printing device 1 for resuming operation also serves as a blocking valve for the ink suction passage 2131, the number of parts in the printing device 1 can be reduced. The configuration can be such that the blocking valve for the ink suction passage 2131 is included separately from the suction pump 214. In this case, various valve configurations can be used, such as valves like the choke valve 16 that allow both manual operation and automatic control, and valves that can be automatically opened and closed by a drive source such as a motor.

[0080] [Hardware Configuration]

[0081] Figure 9 This is a block diagram illustrating the configuration of the printing device 1 in this embodiment. The printing device 1 includes a CPU 201, a ROM 202, a RAM 203, a display unit 209, an input unit 204, a carriage drive unit 207, a printhead drive unit 205, a pump drive unit 216, and a cap drive unit 217. The printing device 1 also includes a choke valve sensor 168, a cap sensor 18, a choke valve drive unit 169, and an I / F 208.

[0082] CPU 201 is the control unit for the overall control of the printing device 1. ROM 202 stores the control program of CPU 201, various data segments, etc. RAM 203 temporarily stores various data segments. For example, CPU 201 reads the program stored in ROM 202 into RAM 203 and executes the program to perform operation control and data processing of the printing device 1. Furthermore, CPU 201 transmits control signals to printhead 14, and printhead 14 ejects ink onto printing media 19 according to the transmitted control signals. In addition, CPU 201 transmits control signals to carriage drive unit 207, pump drive unit 216, and cap drive unit 217 to perform recovery control of printhead 14. Furthermore, the detection results of cap sensor 18 and choke valve sensor 168 are transmitted to CPU 201. CPU 201 can thus determine whether each of cap member 112 and choke valve 16 is in an open or closed state.

[0083] The external I / F 208 is connected to a PC or similar device to receive print data and transmit status signals.

[0084] Display unit 209 displays various user interface screens, such as device information, settings screens, and operation information. Display unit 209 may be formed, for example, by a liquid crystal display. For example, display unit 209 is located in a position easily visible to the user within the main body 111 of housing 11. Input unit 204 receives input from the user. For example, input unit 204 may be a touch panel or hard keys.

[0085] The carriage drive unit 207 includes, for example, a motor, and moves the carriage 13 via a motor driver (not shown) using a control signal transmitted from the CPU 201. In this case, for example, a rack and pinion mechanism (not shown) converts the rotational motion of the motor into reciprocating motion. The pump drive unit 216 includes, for example, a motor, and drives the suction pump 214 via a motor driver (not shown) according to a control signal transmitted from the CPU 201. The cap drive unit 217 includes, for example, a motor, and drives the suction cap 211 via a motor driver (not shown) according to a control signal transmitted from the CPU 201. In this case, for example, a rack and pinion mechanism (not shown) converts the rotational motion of the motor into reciprocating motion.

[0086] The choke valve drive unit 169 includes, for example, an electric motor 1691 (see...) Figure 2 ), reduction gear system 1692 (see Figure 2 The choke valve 16 is switched between an open state and a closed state via a motor driver (not shown) based on a control signal transmitted from the CPU 201.

[0087] It should be noted that Figure 9This is a schematic diagram used to explain the configuration related to choke suction in this embodiment, and the printing device 1 may include other configurations.

[0088] [The operation of the printing equipment]

[0089] This describes the initial filling performed before the first use of the printing device 1. Initial filling is a preparation operation that involves filling the printing device 1 with ink to prepare it for printing after transport. Since the printing device 1 in this embodiment is not filled with ink during transport, initial filling is necessary for the operation of the printing device 1.

[0090] In order to accumulate a sufficient amount of ink in the sub-canister 146 in the printhead 14 after the ink canister 17 is filled with ink, it is preferable to fill the sub-canister with ink from the main canister by performing the following choke suction.

[0091] In the choke suction, the choke valve 16 is set to the closed state, and suction is then performed from the suction cap 211 on the ink ejection port 142 side of the printhead 14. This suction applies a relatively high negative pressure, for example -80 kPa, from the ink ejection port 142. Then, the choke valve 16 is set to the open state to expel air bubbles (air) from the flow path including the sub-canisters 146 in the printhead 14, and the sub-canisters 146 are filled with ink. The high negative pressure applied from the suction cap 211 reduces the pressure of the air layer 144 in each sub-canister 146. Therefore, after the choke suction, the amount of air corresponding to the reduction in the volume of the air layer 144 is replaced by ink, and thus a sufficient amount of ink accumulates in each sub-canister 146. It should be noted that even after the choke suction, the air layer 144 does not completely disappear.

[0092] When suction is performed from the suction cap 211 on the ink ejection port 142 side of the printhead 14 with the choke valve 16 in the open position and the ink supply path not blocked (hereinafter referred to as normal suction), no negative pressure is generated as in choke suction. For example, only about -30 kPa of negative pressure is generated during normal suction. Therefore, it may not be sufficient to fill the sub-tank 146 with ink by normal suction alone.

[0093] The choke valve 16 is a type of valve that blocks the flow passage formed by the supply pipe 15 by flattening a portion of the flow passage from the outer diameter side and bringing the portions of the supply pipe 15 in close contact with each other to block the flow passage, and then releases the flattening to open the flow passage. When the choke valve 16 is released from flattening the supply pipe 15, the tightly contacted portions of the blocked portion separate from each other by the self-restoring force of the supply pipe 15, and the blockage of the supply pipe 15 is opened.

[0094] In many cases, the supply tube 15 is typically made of a soft material such as rubber or an elastomer. However, when the tube is very soft, the self-recovering force of the supply tube 15 tends to be low. Furthermore, as described above, soft materials are adhesive and tend to adhere to the opposite surfaces in the tight contact portion when blocked. Therefore, the time period from the release of the choke valve 16 from its closed state to its open state tends to be longer, depending on the self-recovering force and the degree of adhesion in the tight contact portion, or the time period to the open state may vary.

[0095] In this embodiment, the printing device 1 is transported in a state where the ink tank 17, supply tube 15, or printhead 14 is not filled with ink (dry state) to avoid ink leakage during transportation and reduce manufacturing costs. Therefore, when the choke valve 16 is set to the closed state to perform choke suction during the initial filling, a blockage may occur on the inner diameter side of the supply tube 15 due to the choke valve 16. If a blockage occurs on the inner diameter side of the supply tube 15, it may be impossible to switch from the closed state to the open state.

[0096] Furthermore, when ink adheres to the inner diameter side of the tube, the opening time of the choke valve 16 from the closed state to the open state differs in supply tubes 151 to 154 when ink is being filled in a printing device using multiple color inks. With different opening time periods, ink in the supply tube that first opens reaches the ink ejection port 142 configured to eject that ink first. Therefore, ink drawn from the ink ejection port 142 may be drawn through the surface on which the ink ejection port 142 is formed and into the unopened ink ejection port 142 of the supply tube. Thus, with differences in opening time periods, there is a possibility of so-called ink mixing occurring and a decrease in print quality. Ink mixing is the phenomenon of different colored inks mixing as they pass through the surfaces of the ink ejection ports of the printhead.

[0097] Therefore, in the printing apparatus 1 of this embodiment, before performing choke suction during initial filling, normal suction is performed with the choke valve set to the open state, and ink is drawn through normal suction to a predetermined position in the ink supply passage 155. In this embodiment, the predetermined position includes the portion of the tube blocked by the choke valve 16. This operation first sets the portion of the tube blocked by the choke valve 16 to a state where the tube is wetted with ink (also called a wetted state). Therefore, the adhesion of the blocked portion of the supply tube 15 to the inner diameter side is suppressed.

[0098] It should be noted that adhesion of the supply pipe 15 in the blocked portion caused by the choke valve 16 can occur not only in pinch valve methods, but also in any valve that generally uses flexible rubber or elastomers. For example, similar adhesion in the blocked portion may also occur in diaphragm valves using rubber or elastomers.

[0099] Figure 10 This is a flowchart illustrating an example of the processing of CPU 201 during the initial ink filling. For example, CPU 201 reads a program stored in ROM 202 into RAM 203 and executes the program to implement this flowchart. Furthermore, this flowchart begins, for example, when the printing device 1 begins the initial filling process.

[0100] In S1001, CPU 201 determines whether the suction cap 211 has closed the ink ejection port 142. If the suction cap 211 has not closed the ink ejection port 142 ("No" in S1001), in S1002, CPU 201 performs processing to close the ink ejection port 142. If the suction cap 211 has closed the ink ejection port 142 ("Yes" in S1001), CPU 201 skips S1002 and proceeds to S1003.

[0101] In S1003, the CPU 201 determines whether the choke valve sensor 168 indicates that the choke valve 16 is in the open state. The printing device 1 of this embodiment is transported with the choke valve 16 set to the open state. Therefore, the choke valve sensor 168 should indicate the open state before initial filling. However, it is conceivable that the choke valve 16 might be set to the closed state due to user error or manual operation. Therefore, this determination step is performed.

[0102] If the choke valve sensor 168 indicates a closed state (no in S1003), in S1004, a process to drive the choke valve 16 to an open state (opening process) is performed.

[0103] Figure 11 Part (a) is a flowchart explaining the process of actuating the choke valve to the open state. By using... Figure 11 The details of the processing in S1004 are described in part (a). In S1101, CPU 201 executes the process of driving the choke valve 16 to the open state. In S1102, CPU 201 determines whether the choke valve sensor 168 indicates that the state of the choke valve 16 is open. If the choke valve sensor 168 indicates the open state (yes in S1102), CPU 201 confirms that the sensor is in the open state and terminates the process of driving the choke valve to the open state. Then CPU 201 proceeds to... Figure 10 S1005.

[0104] If the choke valve sensor 168 indicates a closed state (No in S1102), in S1103, the CPU 201 determines whether the number of times the process of driving the choke valve to the open state has been executed has exceeded a predetermined number of drives (the so-called retry drive count). Alternatively, the CPU 201 may determine whether a predetermined time period has elapsed since the first execution of the process of setting the choke valve to the open state in S1101. If the number of times the process has been executed has not exceeded the predetermined number of drives (No in S1113), the CPU 201 returns to S1101 and repeats the process from S1101 to S1102. If the number of times the process has been executed has exceeded the predetermined number of drives (Yes in S1103), problems such as malfunctions may occur. Therefore, the CPU 201 proceeds to... Figure 10 The S1014 function notifies the user of a choke valve sensor error.

[0105] return Figure 10 Continuing with the flowchart explanation, after CPU 201 confirms in S1004 that the choke valve sensor 168 is in the open state, in S1005, CPU 201 begins driving the suction pump 214. Since the choke valve 16 is in the open state in this step, normal suction operation begins in this step.

[0106] In S1006, the CPU 201 determines whether the pump drive has continued until the pump drive amount reaches a pre-stored drive amount Vn. The drive amount Vn is the drive amount of the suction pump 214 when ink from each ink tank 17 reaches a position including a predetermined position via normal suction. In this embodiment, the predetermined position includes the position of the portion of the tube blocked by the choke valve 16. The CPU 201 can determine whether the ink has reached the position including the predetermined position based on the drive time period of the suction pump 214, rather than the drive amount Vn. As described above, the ink reaches the predetermined position via normal suction by the suction pump 214 of the drive recovery unit 21 reaching a predetermined drive amount or a predetermined drive time period. The predetermined drive amount Vn or the predetermined drive time period can be predetermined through calculation, experimentation, etc.

[0107] CPU 201 can select the driving amount Vn or driving time period to be used in this determining step from a plurality of pre-stored driving amounts or driving time periods, depending on, for example, the physical properties (e.g., viscosity) of the ink used in printing device 1, ambient temperature, air pressure, etc.

[0108] When the driving amount of the suction pump reaches Vn (yes in S1006), in S1007, the CPU 201 stops driving the suction pump 214.

[0109] Then, in S1008, a process of setting the choke valve 16 to the closed state (blocking process) is performed, and a choke suction process is started. In this embodiment, normal suction is performed before the blocking suction is performed, and ink is brought to the location including the blocking portion of each supply tube 15 before the process of S1008 is performed. Therefore, at the start of the process of S1008, the blocking portion of the supply tube 15 is wet, and adhesion in the blocking portion of the supply tube 15 caused by choke suction is suppressed.

[0110] Figure 11 Part (b) is a flowchart explaining the process of driving the choke valve to the closed state in S1008. By using... Figure 11 Part (b) describes the details of the processing of S1008.

[0111] In S1111, CPU 201 executes the process of driving choke valve 16 to the closed state. In S1112, CPU 201 determines whether choke valve sensor 168 indicates that the state of choke valve 16 is closed. If choke valve sensor 168 indicates the closed state (yes in S1112), CPU 201 confirms that the sensor is closed and terminates the process of driving choke valve to the closed state. Then CPU 201 proceeds to... Figure 10 In S1009, if the choke valve sensor 168 indicates an open state (No in S1112), in S1113, the CPU 201 determines whether the number of times the process of driving the choke valve to the closed state has been executed has exceeded a predetermined number of drives (the so-called retry drive count). Alternatively, the CPU 201 may determine whether a predetermined time period has elapsed since the first execution of the process of setting the choke valve to the closed state in S1111. If the number of times the process has been executed has not exceeded the predetermined number of drives (No in S1103), the CPU 201 returns to S1111 and repeats the process from S1111 to S1112. If the number of times the process has been executed has exceeded the predetermined number of drives (Yes in S1113), problems such as malfunctions may occur. Therefore, the CPU 201 proceeds to... Figure 10 The S1014 function notifies the user of a choke valve sensor error.

[0112] return Figure 10 Continuing with the flowchart explanation. After CPU 201 confirms in S1008 that the choke valve sensor 168 is in the closed state, in S1009, CPU 201 begins driving the suction pump 214. Since the choke valve 16 is in the closed state in this step, the choke suction operation begins in this step.

[0113] In S1010, CPU 201 determines whether the pump has been driven until the pump's drive amount reaches a pre-stored drive amount Vc. Driving the suction pump 214 until the drive amount reaches the drive amount Vc allows a relatively high negative pressure, such as approximately -80 kPa, to be applied to the ink ejector nozzle 142 side. CPU 201 may determine whether the suction pump 214 has been driven until the pressure reaches the predetermined negative pressure based on factors such as the duration of the suction pump 214's drive, rather than the drive amount Vc.

[0114] CPU 201 can select the driving amount Vc or driving time period to be used in this determining step from a plurality of pre-stored driving amounts or driving time periods, depending on, for example, the physical properties (e.g., viscosity) of the ink used in printing device 1, ambient temperature, air pressure, etc.

[0115] When the driving amount of the suction pump reaches Vc (yes in S1010), in S1011, the CPU 201 stops driving the suction pump 214. Then, in S1012, the process of setting the choke valve 16 to the open state is executed. Since the process of setting the choke valve 16 to the open state is the same as in S1004, its description is omitted.

[0116] In this embodiment, adhesion to the blockage portion of the supply pipe 15 caused by choke suction is suppressed. Therefore, the situation where the choke valve 16 is not set to the open state even when the CPU 201 performs the process of setting the choke valve 16 to the open state after choke suction is suppressed, and the situation where the opening time of the choke valve 16 is set to the open state changes is suppressed.

[0117] If the choke valve sensor 168 is confirmed to be open in S1012, in S1013, the CPU 201 determines whether a waiting period Tc has elapsed since the confirmation of the open state. The waiting period Tc is a pre-stored value and is the time interval from the confirmation of the choke valve 168 being open in S1012 to the moment when the supply pipe 15 and printhead 14 are filled with ink. If the waiting period Tc has elapsed, the initial filling process terminates. Therefore, the printing device 1 is set to a state where printing can begin.

[0118] CPU 201 can select a waiting time period Tc to be used in this determining step from a number of predetermined time periods, depending on, for example, the physical properties of the ink used (e.g., viscosity), ambient temperature, air pressure, etc.

[0119] It should be noted that the initial choke-pump operation can be performed multiple times. For example, in high-altitude areas, the ink fill rate to the sub-tank during choke-pump is lower than in low-altitude areas. In this case, the ink fill amount to the sub-tank can be ensured by repeating the choke-pump operation multiple times.

[0120] According to the above embodiment, the blockage of the ink supply path that cannot be opened after choke suction can be suppressed.

[0121] Despite Figure 10 The flowchart illustrates the application of the method of this embodiment to initial filling, but the control method of this embodiment is not limited to application to initial filling. Figure 10 Similar controls to the flowchart can be applied to ink filling involving choke suction, except during the initial filling.

[0122] <Second Embodiment>

[0123] In the first embodiment, a method is described in which the position reached by each ink type before normal suction is performed is set to the portion blocked by the choke valve 16. In this embodiment, a method is described in which the position reached by the ink before performing blocking suction is set downstream of the blocked portion to suppress the flattening of the supply tube 15 other than the blocked portion during blocking suction. In this embodiment, the main differences from the first embodiment are described. Parts not specifically described are the same configuration and processing as in the first embodiment.

[0124] When the choke valve 16 blocks the supply pipe 15 and choke suction begins, a relatively high negative pressure of approximately -80 kPa is applied to the ink ejector 142 side via the suction cap 211. Before choke suction, when the ink's arrival point is near the portion blocked by the choke valve 16, the pressure loss is very small because the interior of the supply pipe 15 from the ink ejector 142 to the choke valve 16 is mostly air. Therefore, before choke suction, when the ink's arrival point is near the portion blocked by the choke valve 16, the negative pressure within the supply pipe 15 is, for example, approximately -75 kPa, and has a value close to the negative pressure at the ink ejector 142. The difference in negative pressure between the supply pipe 152 and the ink ejector 142 is caused by pressure loss due to air in the ink supply passage 155 upstream of the printhead 14.

[0125] Figure 12 This is a schematic diagram showing the supply tube 15 and the print head 14. Figure 12 Part (a) is a schematic illustration of the state where the suction cap 211 is not in contact with the ink ejection nozzle 142 and is open, and the choke valve 16 is in the open state. Specifically, Figure 12 Part (a) is a diagram illustrating the situation without choke suction. (See diagram for example.) Figure 12 As shown in section (a), the supply tube 15 is not flattened and is in a normal state when no choke suction is performed.

[0126] at the same time, Figure 12Part (b) is a diagram showing the choke valve 16 performing choke suction in the closed state and with the suction cap 211 in contact with the ink jet nozzle 142. Figure 12 Part (b) shows the supply tube 15 being flattened within a certain range along the longitudinal direction. As mentioned above, the supply tube 15 is flexible to perform its function as a tube and is easily deformable. Therefore, when a high negative pressure is applied to the supply tube 15, it is possible for the supply tube 15 to be flattened by atmospheric pressure within a certain range along the longitudinal direction. Flattening of the supply tube 15 may occur throughout the entire range from near the connector portion 182, which serves as the connection portion to the head, to the choke valve 16. When the supply tube 15 is flattened during choke suction as described above, blockage will occur in the portion other than the portion blocked by the choke valve 16, regardless of whether the choke valve 16 is in the closed or open state. This narrows the flow path and destabilizes the ink's connectivity, potentially preventing normal ink filling.

[0127] It is conceivable to form the supply tube 15 using a tube that is not flattened by the negative pressure in choke suction. In this case, it is necessary to select a harder material as the material for the supply tube 15 or increase the thickness of the tube. Therefore, in order to form the supply tube 15 using a tube that is not flattened by the negative pressure in choke suction, it is necessary to adopt a condition that increases the rigidity of the tube in terms of qualitative properties, i.e., a tube with lower flexibility. When the supply tube 15 is formed from a tube with lower flexibility, the size of the printing device 1 increases. In addition, the freedom of configuration of the supply tube 15 is reduced, and the manufacturing cost increases.

[0128] In this embodiment, the CPU 201 controls the suction pump 214 such that the ink reaches a predetermined position, for example, including the position of the filter 145 of the printhead 14, through normal suction performed before choke suction. In this embodiment, Figure 10 The drive quantity Vn in S1006 is the drive quantity when ink reaches the filter 145 of the printhead 14.

[0129] As described above, the filter 145 is formed of a mesh member with finer pores than the foreign matter to trap it. Wetting the entire filter 145 with ink results in pressure loss due to ink flow resistance at the fine mesh and the bending force of the ink. Assume the ink reaches the location including the filter 145 before choking suction. In this case, if a negative pressure of, for example, -80 kPa is applied near the ink nozzle 142 by choking suction, the negative pressure in the supply tube 15 is, for example, about -60 kPa. In this embodiment, the absolute value of the negative pressure in the supply tube 15 can therefore be less than the absolute value of the negative pressure near the ink nozzle 142. Therefore, in this embodiment, it is sufficient to use a tube that can withstand -60 kPa and is not crushed at -60 kPa as the supply tube 15, rather than a tube with lower flexibility that can withstand -80 kPa. Therefore, in this embodiment, a tube with higher flexibility than in the first embodiment can be selected as the supply tube 15.

[0130] Alternatively, the predetermined position to which the ink reaches through normal suction performed before choke suction can be set to include the position of the ink ejector 142. In this case, for Figure 10 The determined driving amount Vn in S1006 is the driving amount when ink reaches the ink ejection port 142.

[0131] Because the ink ejector 142 consists of numerous fine pores, pressure loss occurs due to the ink flow resistance generated by these pores and the meniscus force of the ink ejector 142. Furthermore, the filter 14 upstream of the ink ejector 142 is in a state of being wetted by ink. Therefore, the synergistic effect of the wetted ink ejector 142 and the filter 145 allows the absolute value of the negative pressure in the supply pipe 15 to be reduced compared to the condition where ink reaches the filter 145. Assuming the ink reaches the location including the ink ejector 142 before choke suction, in this case, if a negative pressure of, for example, -80 kPa is applied near the ink ejector 142, the negative pressure in the supply pipe 15 can be, for example, a smaller absolute value of -50 kPa.

[0132] In this case, it is only necessary to select a pipe that can withstand -50 kPa and will not be flattened at -50 kPa as the supply pipe 15, instead of selecting a pipe with lower flexibility that can withstand -80 kPa. Therefore, in this embodiment, a pipe with higher flexibility can be selected.

[0133] As described above, according to this embodiment, choke suction can be performed while solving the problem of the tube being flattened within a certain range along the longitudinal direction without increasing the tube's hardness, thickness, etc.

[0134] <Third Embodiment>

[0135] In the first embodiment, a method for determining whether ink has reached a predetermined position before performing choke suction was described, which involved performing the determination based on the drive amount of the suction pump. In this embodiment, a method for determining whether ink has reached a predetermined position is described using a sensor. This embodiment primarily describes the differences from the first embodiment. Parts not specifically described are the same configuration and processing as in the first embodiment.

[0136] Figure 13 This is a schematic diagram illustrating the ink supply path. In this embodiment, as in the first embodiment, it is assumed that the predetermined position where the ink arrives before choke suction is the portion blocked by the choke valve 16. An ink arrival sensor 30 is disposed in the supply tube 15 forming the ink supply path 155 of this embodiment, serving as a unit for detecting the arrival of ink downstream of the choke valve 16. The ink arrival sensor 30 is, for example, an optical sensor, such as a light interruptor. Furthermore, the supply tube 15 of this embodiment is made of a transparent material, the degree of which allows the arrival of ink to be determined by the ink arrival sensor 30. The ink arrival sensor 30 is arranged such that the optical axis center 30a of the ink arrival sensor 30 passes through the transparent supply tube 15. Therefore, the ink arrival sensor 30 can detect the arrival of ink in the supply tube 15. The method for detecting the presence or absence of ink arrival is not limited to optical sensors, and various known sensors and configurations can be applied.

[0137] Figure 14 This is a flowchart illustrating an example of the process during the initial filling of ink in this embodiment. Since S1401 to S1405 are the same as S1001 to S1005, their description is omitted.

[0138] In this embodiment, after normal suction begins, in S1406, the CPU 201 determines whether ink has been detected by the ink arrival sensor 30. If ink has reached the optical axis center 30a of the ink arrival sensor 30, the CPU 201 determines that ink has been detected by the ink arrival sensor 30. Since S1407 to S1414 are the same as S1007 to S1014, their description is omitted.

[0139] The ink arrival sensor 30 is arranged, for example, for each of the supply pipes 151 to 154 of the corresponding color. In this case, in S1406, the CPU 201 determines that ink arrival has occurred if all the ink arrival sensors 30 of the corresponding color have detected ink. Specifically, the determination in S1406 uses the result of the ink arrival sensor 30 that detected ink arrival last among the ink arrival sensors 30 of the corresponding color. Therefore, based on conditions such as the path length of the supply pipe 15, ink viscosity, etc., the ink arrival sensor 30 can be arranged in the supply pipe 15 that forms the flow path of the color where ink arrival is later. For example, the ink arrival sensor 30 can be arranged only in the supply pipe 15 that forms the flow path of the color where ink arrival is latest. In the case where there are multiple flow paths where ink arrival is likely to be latest, the ink arrival sensor 30 can be arranged in the supply pipe 15 that forms these flow paths. Limiting the flow paths of the ink arrival sensor 30 as described above reduces the number of ink arrival sensors arranged and thus reduces manufacturing costs.

[0140] <Other Embodiments>

[0141] Although several embodiments have been described above, the technology disclosed herein is not limited to the foregoing embodiments, and various combinations, changes, modifications, etc., can be made without departing from the spirit or scope of the technology disclosed herein.

[0142] This disclosure is not limited to the foregoing embodiments, and various changes and modifications can be made without departing from the spirit and scope of the technology disclosed herein. Therefore, the appended claims have been added to disclose the scope of the invention.

[0143] This application claims priority based on Japanese Patent Application No. 2021-020600, filed on February 12, 2021, the entire contents of which are incorporated herein by reference.

Claims

1. A printing apparatus, the printing apparatus comprising: A canister configured to contain liquid to be supplied to a printhead, the printhead ejecting the liquid from a nozzle; A supply passage configured to supply the liquid from the tank to the printhead; A suction unit configured to suction the liquid from the jet nozzle; A valve, which is disposed at a first position in the supply passage and configured to switch between an open state in which the supply passage is connected and a closed state in which the supply passage is blocked; as well as Control unit, configured to control the valve and the suction unit, wherein The control unit Control is performed on the first suction, in which the valve is set to the open state, the suction unit performs suction, and the suction unit stops suction when the liquid reaches the first position or a second position downstream of the first position. After the first suction is completed, control is applied to the second suction, in which the valve is set to the closed state, and the suction unit performs suction. After the second suction, control is executed to set the valve to the open state. In the case where the printing device is in a state where the liquid has not yet reached the first position from the tank, the control unit performs control of the second suction after the first suction.

2. The printing apparatus of claim 1, wherein the second position includes one of the position of the filter in the printhead and the position of the nozzle.

3. The printing apparatus of claim 1, further comprising a detection unit configured to detect arrival of the liquid at the second position in the supply path, wherein... The control unit performs control of the second suction after the detection unit detects the arrival of the liquid.

4. The printing device according to claim 1, wherein The suction unit includes a pump for performing suction, and The control unit performs control over the first suction by executing control to set the valve to the open state and then drive the pump with a predetermined drive amount.

5. The printing apparatus according to claim 1, wherein The suction unit includes a pump for performing suction, and The control unit performs control of the first suction by setting the valve to the open state and then driving the pump for a predetermined time period.

6. The printing apparatus of claim 1, wherein the valve is set to a closed state by pressing the tube forming the supply passage and blocking the supply passage.

7. The printing apparatus of claim 6, wherein the tube is formed of a flexible member.

8. The printing apparatus of claim 1 further includes a drive unit configured to be driven by the control unit and to switch the valve between a closed state and an open state.

9. The printing apparatus according to any one of claims 1 to 8, wherein the valve is in the open state during transport of the printing apparatus.

10. The printing apparatus according to claim 1, wherein, After the second suction is performed and the suction unit stops suction, the control unit performs control to set the valve to the open state.

11. The printing apparatus of claim 1, further comprising a plurality of supply passages, wherein the valve opens and closes the plurality of supply passages.

12. A method for controlling a printing device, comprising: A can, configured to contain liquid to be supplied to a printhead, which ejects the liquid from an injection nozzle. A supply passage configured to supply the liquid from the tank to the printhead. A suction unit configured to draw the liquid from the jet nozzle, and A valve, disposed at a first position in the supply passage and configured to switch between an open state in which the supply passage is connected and a closed state in which the supply passage is blocked, the method comprising: The first step is to set the valve to the open state and make the suction unit perform suction, and stop suction when the liquid reaches the first position or a second position downstream of the first position; The second step, namely, before the liquid has reached the first position from the tank, after the first step is completed, setting the valve to the closed state and causing the suction unit to perform a predetermined suction; and The third step, that is, after the second step, is to set the valve to the open state.

Images