Liquid level detection unit and liquid dispensing device

Abstract

The present invention provides a liquid level detection unit and a liquid dispensing device that can improve the installation flexibility of the liquid level detection unit. [Solution] The liquid level detection unit comprises a liquid level tube extending along the height direction and opening to the atmosphere at the top, an inlet section to which a flow path is connected for allowing liquid to flow from a tank to the liquid level tube and which is connected to a liquid discharge head for discharging liquid, a reading section that reads the liquid level in the liquid level tube and outputs the reading result to a control unit, and a base section on which the liquid level tube, inlet section and reading section are provided. The liquid level tube is translucent. The height of the reference bottom surface of the liquid level tube is the same as the height of the reference bottom surface of the tank.

Description

Technical Field

[0001] The present invention relates to a liquid level detection unit and a liquid discharge device.

Background Art

[0002] For example, as disclosed in Patent Document 1, there is disclosed a liquid discharge device including a liquid discharge head that discharges liquid from a tank and a sensor module that detects light incident from the tank. In such a liquid discharge device, the liquid level in the tank is detected based on a detection signal from a sensor module, which is an example of a liquid level detection unit.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in such a liquid discharge device, it is necessary to install the liquid level detection unit on the side surface of the tank in order to detect the light incident from the tank. Therefore, the liquid level detection unit cannot be installed at a position far from the tank. Thus, it is desired to improve the degree of freedom in installing the liquid level detection unit.

Means for Solving the Problems

[0005] A liquid level detection unit that solves the above problems comprises a liquid level tube extending along the height direction and opening to the atmosphere at the top, an inlet section to which a flow path is connected for introducing liquid from a tank connected to a liquid discharge head that discharges liquid into the liquid level tube, a reading section that reads the liquid level in the liquid level tube and outputs the reading result to a control unit, and a base section on which the liquid level tube, the inlet section, and the reading section are provided, wherein the liquid level tube is translucent, and the height of the reference bottom surface of the liquid level tube is the same as the height of the reference bottom surface of the tank.

[0006] A liquid dispensing device that solves the above problems comprises a liquid dispensing head for dispensing liquid, a tank connected to the liquid dispensing head, a liquid level detection unit for detecting the liquid level in the tank, a flow path for allowing liquid to flow from the tank to the liquid level detection unit, and a control unit. The liquid level detection unit comprises a liquid level pipe extending along the height direction and open to the atmosphere at the top, an inlet to which the flow path is connected, a reading unit that outputs a reading result of reading the liquid level in the liquid level pipe to the control unit, and a base portion on which the liquid level pipe, the inlet, and the reading unit are provided. The liquid level pipe is translucent, the height of the reference bottom surface of the liquid level pipe is the same as the height of the reference bottom surface of the tank, and the control unit detects the liquid level in the tank based on the reading result from the reading unit. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is a schematic diagram of a liquid dispensing device according to the first embodiment. [Figure 2] Figure 2 is a schematic diagram of the liquid dispensing device of the first embodiment. [Figure 3] Figure 3 is a schematic diagram of the liquid level tube of the first embodiment. [Figure 4] Figure 4 is a side view of the liquid level detection unit of the first embodiment. [Figure 5] Figure 5 is a front view of the liquid level detection unit according to the first embodiment. [Figure 6] Figure 6 is a schematic diagram of the image captured in the first embodiment. [Figure 7]Figure 7 is a schematic diagram of the corrected image of the first embodiment. [Figure 8] Figure 8 is a side view of the liquid level detection unit of the second embodiment. [Figure 9] Figure 9 is a front view of the liquid level detection unit according to the second embodiment. [Figure 10] Figure 10 is a schematic diagram of a liquid dispensing device according to the third embodiment. [Figure 11] Figure 11 is a schematic diagram of the liquid dispensing device of the fourth embodiment. [Modes for carrying out the invention]

[0008] [First Embodiment] The following description will explain one embodiment of a liquid dispensing device equipped with a liquid level detection unit with reference to the drawings. In the following description, with the liquid dispensing device installed on a horizontal surface, the axis intersecting the horizontal surface will be defined as the Z-axis, the axis intersecting the Z-axis will be defined as the X-axis, and the axis intersecting both the X-axis and the Z-axis will be defined as the Y-axis. One direction along the X-axis will be defined as the first width direction X1, and the other direction along the X-axis will be defined as the second width direction X2. The direction along the X-axis is an example of the width direction. One direction along the Y-axis will be defined as the front Y1, and the other direction along the Y-axis will be defined as the rear Y2. The direction along the Y-axis is an example of the front-to-back direction. The upward direction along the Z-axis will be defined as the upward Z1, and the downward direction along the Z-axis will be defined as the downward Z2. The direction along the Z-axis is an example of the height direction. Viewing from the front Y1 will simply be referred to as a front view. Viewing from the direction along the X-axis will simply be referred to as a side view.

[0009] <Configuration of liquid dispensing device 11> As shown in Figure 1, the liquid ejection device 11 is configured to perform printing by ejecting liquid onto the medium 99. The liquid ejection device 11 may also be an inkjet printer that performs printing by ejecting ink, which is an example of a liquid, onto the medium 99.

[0010] The liquid dispensing device 11 comprises a liquid dispensing unit 12, a medium support unit 13, and a transport unit 14. The liquid dispensing unit 12 is configured to dispense liquid onto a medium 99. The liquid dispensing unit 12 is configured to dispense liquid onto a medium 99 supported by the medium support unit 13. The liquid dispensing unit 12 is configured to dispense liquid onto a medium 99 that is transported forward Y1.

[0011] The liquid dispensing unit 12 comprises a liquid dispensing head 15, a carriage 16, and a carriage guide 17. In other words, the liquid dispensing device 11 comprises a liquid dispensing head 15, a carriage 16, and a carriage guide 17.

[0012] The liquid ejection head 15 is configured to eject liquid. In this embodiment, the liquid ejection head 15 ejects liquid downward Z2. The liquid ejection head 15 is configured to be supported on the bottom surface of the carriage 16. The liquid ejection head 15 prints an image onto the medium 99 by ejecting liquid onto the medium 99.

[0013] The carriage 16 is configured to support the liquid discharge head 15. The carriage 16 is supported by a carriage guide 17. The carriage guide 17 is configured to extend along the X-axis. The carriage 16 is configured to reciprocate along the carriage guide 17 by a driving force from a carriage drive unit (not shown).

[0014] This configures the carriage 16 to move along the X-axis while supporting the liquid ejection head 15. In other words, the liquid ejection head 15 is movable along the X-axis. The carriage 16 is configured to move along the X-axis across the printing area 18 and the retraction area 19.

[0015] The printing area 18 is an area for performing printing on the medium 99. The printing area 18 is provided at the center of the liquid ejection device 11. The retraction area 19 is an area for retracting when the liquid ejection head 15 does not perform printing. The retraction area 19 is provided in the first width direction X1 with respect to the printing area 18. That is, the retraction area 19 is provided in the first width direction X1 with respect to the center of the liquid ejection device 11. The retraction area 19 may be an area for performing maintenance on the liquid ejection head 15. The carriage 16 waits at the standby position in the retraction area 19. When the carriage 16 is arranged at the standby position, the position where the liquid ejection head 15 is arranged corresponds to an example of a specified position.

[0016] The medium support portion 13 is configured to support the medium 99. The medium support portion 13 is provided so as to extend along the X-axis. The medium support portion 13 is configured to support the medium 99 conveyed by the conveyance portion 14. The medium support portion 13 is provided at a position facing the liquid ejection head 15 in the printing area 18. The medium support portion 13 is configured to support the medium 99 when the liquid ejection head 15 ejects liquid toward the medium 99.

[0017] The conveyance portion 14 is configured to convey the medium 99 along the conveyance path 20. The conveyance path 20 is a path along which the medium 99 is conveyed in the conveyance direction. The liquid ejection device 11 includes the conveyance path 20. The conveyance portion 14 is configured to convey the medium 99 forward in the Y1 direction while being supported by the medium support portion 13. The forward Y1 corresponds to an example of the conveyance direction.

[0018] The conveyance portion 14 may include a plurality of roller pairs. The conveyance portion 14 may include a conveyance roller pair 21. The conveyance roller pair 21 is configured to convey the medium 99 upstream in the conveyance direction of the medium support portion 13.

[0019] The liquid ejection device 11 includes a tank 30. The tank 30 stores the liquid to be ejected onto the medium 99. The liquid ejection device 11 may include a plurality of tanks 30A to 30D. The liquid ejection device 11 may include a plurality of tanks 30A to 30D corresponding to the colors of the liquid.

[0020] Multiple tanks 30A to 30D are each configured in the same way. Hereafter, multiple tanks 30A to 30D may be referred to simply as tank 30. At least one combination of multiple tanks 30A to 30D may have different sizes or capacities.

[0021] Multiple tanks 30A to 30D are located in the first width direction X1 relative to the transport path 20. Multiple tanks 30A to 30D are located in front of the liquid discharge head 15, which is positioned in standby position, in Y1.

[0022] As shown in Figure 2, each of the multiple tanks 30A to 30D is equipped with a liquid storage chamber 31. The liquid storage chamber 31 is provided to contain liquid. The liquid storage chamber 31 may also be a container for containing liquid.

[0023] Each of the multiple tanks 30A to 30D is equipped with an injection section 32. The injection section 32 is equipped with an injection hole into which liquid is injected. The injection section 32 is provided above Z1 in each of the multiple tanks 30A to 30D.

[0024] Each of the multiple tanks 30A to 30D is equipped with a tank atmospheric vent 33. The tank atmospheric vent 33 is provided above Z1 of each of the multiple tanks 30A to 30D. Each of the tank atmospheric vent 33 may be a hole for releasing the air inside the tank 30 to the outside.

[0025] As shown in Figure 1, the liquid dispensing device 11 includes a supply channel 22. The liquid dispensing device 11 may have multiple supply channels 22, each corresponding to a plurality of tanks 30A to 30D. The supply channel 22 is a channel that connects the plurality of tanks 30A to 30D to the liquid dispensing head 15. In other words, the plurality of tanks 30A to 30D are connected to the liquid dispensing head 15 via the supply channel 22. The supply channel 22 may be, for example, a tube.

[0026] The liquid dispensing device 11 includes a control unit 23. The control unit 23 comprehensively controls the liquid dispensing device 11. The control unit 23 controls various operations performed by the liquid dispensing device 11. The control unit 23 may be configured as a circuit including α: one or more processors that perform various processes according to a computer program, β: one or more dedicated hardware circuits that perform at least some of the various processes, or γ: a combination thereof. The hardware circuit is, for example, an application-specific integrated circuit. The processor includes a CPU and memory such as RAM and ROM, and the memory stores program code or instructions configured to cause the CPU to perform processes. Memory, or computer-readable media, includes any readable media that can be accessed by a general-purpose or dedicated computer.

[0027] The control unit 23 displays various information on a display unit (not shown). The control unit 23 receives user instructions from an operation unit (not shown). The liquid dispensing device 11 may be able to communicate with a terminal device (not shown). The control unit 23 may receive user instructions from the terminal device.

[0028] The liquid dispensing device 11 includes a liquid level detection unit 40. The liquid level detection unit 40 outputs data to the control unit 23 that enables the detection of the liquid level L of the liquid contained in each of the multiple tanks 30A to 30D. The liquid level L indicates the height of the liquid surface.

[0029] The liquid level detection unit 40 is located in the first width direction X1 relative to the transport path 20. The liquid level detection unit 40 is located in the rear Y2 relative to the liquid discharge head 15, which is positioned in standby.

[0030] Thus, in the first embodiment, the multiple tanks 30A to 30D and the liquid level detection unit 40 are positioned to sandwich the liquid discharge head 15 in the direction along the Y axis when the liquid discharge head 15 is in the standby position. In other words, the multiple tanks 30A to 30D and the liquid level detection unit 40 are positioned to sandwich the range of movement of the liquid discharge head 15. At least a portion of the liquid level detection unit 40 may be positioned to overlap at least a portion of the multiple tanks 30A to 30D in a front view.

[0031] The liquid dispensing device 11 is equipped with connection passages 50. The liquid dispensing device 11 may be equipped with multiple connection passages 50, each corresponding to one of the multiple tanks 30A to 30D. Each of the multiple connection passages 50 connects the multiple tanks 30A to 30D to the liquid level detection unit 40.

[0032] As shown in Figure 2, each of the multiple connection paths 50 is equipped with a flow path 51. In other words, the liquid discharge device 11 is equipped with multiple flow paths 51. The flow paths 51 are configured to connect the tank 30 and the liquid level detection unit 40. The flow paths 51 are connected to the lower Z2 side of the tank 30. The flow paths 51 are configured to allow the liquid contained in the tank 30 to flow into the liquid level detection unit 40.

[0033] Each of the multiple connection lines 50 is provided with a connecting passage 52. In other words, the liquid discharge device 11 is provided with multiple connecting passages 52. The connecting passages 52 are configured to connect the tank 30 and the liquid level detection unit 40. The connecting passages 52 are connected to the upper Z1 side of the tank 30. The connecting passages 52 are configured to allow air from the liquid level detection unit 40 to flow into the tank 30 by connecting the tank 30 and the liquid level detection unit 40.

[0034] <Configuration of liquid level detection unit 40> Here, the configuration of the liquid level detection unit 40 will be explained using Figures 2 to 5. In Figure 2, multiple tanks 30A to 30D are represented and explained as tank 30.

[0035] As shown in Figure 4, the liquid level detection unit 40 includes a base portion 41. The liquid level detection unit 40 includes a liquid level pipe 42, an inlet portion 43, and a connecting portion 44. The liquid level detection unit 40 may include multiple liquid level pipes 42, multiple inlet portions 43, and multiple connecting portions 44 to correspond to multiple tanks 30A to 30D, respectively. The liquid level detection unit 40 includes a reading portion 45 and a support portion 46.

[0036] As shown in Figures 4 and 5, the base portion 41 is the base component of the liquid level detection unit 40. The base portion 41 is a component that holds the liquid level tube 42, the inlet portion 43, the communication portion 44, and the reading portion 45. In other words, the base portion 41 is provided with the liquid level tube 42, the inlet portion 43, the communication portion 44, and the reading portion 45. The base portion 41 may be provided in the shape of a plate. The base portion 41 is made of resin, but may be made of a material other than resin. The base portion 41 may be a different color from the liquid so that the liquid level L of the liquid contained in the liquid level tube 42 can be read by the reading portion 45.

[0037] The base portion 41 comprises a first surface 41A and a second surface 41B. The second surface 41B is the back surface of the first surface 41A. A liquid level tube 42, a reading section 45, and a support section 46 are provided on the first surface 41A side. An inlet section 43 and a communication section 44 are provided on the second surface 41B side.

[0038] As shown in Figure 5, the base portion 41 is provided with a plurality of reference lines 41C. In other words, the liquid level detection unit 40 is provided with a plurality of reference lines 41C. The plurality of reference lines 41C are provided on the first surface 41A. The reference lines 41C are provided in the region where the liquid level tube 42 is located.

[0039] The multiple reference lines 41C are lines that indicate the reference liquid level L of the liquid level tube 42. The multiple reference lines 41C are lines that indicate the reference liquid level L of each of the multiple liquid level tubes 42A to 42D. The multiple reference lines 41C are arranged so as to be aligned along the Z-axis.

[0040] The liquid level tube 42 is provided on the first surface 41A side. Multiple liquid level tubes 42A to 42D are provided on the first surface 41A side. Multiple liquid level tubes 42A to 42D are provided so as to be aligned in the direction along the X-axis. In other words, multiple liquid level tubes 42A to 42D are provided so as to be aligned in a direction that is included in the first surface 41A and intersects with the Z-axis.

[0041] As shown in Figures 2 and 3, the liquid level tube 42 is configured to contain liquid. The liquid level tube 42 is translucent. The liquid level tube 42 may be transparent or not, as long as the liquid level L of the contained liquid can be read by the reading unit 45. The liquid level tube 42 is tubular and extends in the direction along the Z axis. The liquid level tube 42 is configured to be open to the atmosphere at the top Z1.

[0042] The liquid level tube 42 is a component through which liquid flows from the tank 30. The liquid level tube 42 has a smaller liquid capacity than the tank 30. The multiple liquid level tubes 42A to 42D are components through which liquid flows from the corresponding multiple tanks 30A to 30D.

[0043] As shown in Figure 2, the height of the reference bottom surface 49 of the liquid level tube 42 is the same as the height of the reference bottom surface 34 of the tank 30. In other words, the liquid level detection unit 40 is positioned so that the reference bottom surface 49 of the liquid level tube 42 and the reference bottom surface 34 of the tank 30 are at the same height.

[0044] As a result, when liquid from tank 30 flows into the liquid level tube 42, the liquid level L in the liquid level tube 42 becomes the same as the liquid level L in tank 30. In other words, the liquid levels L in multiple liquid level tubes 42 become the same as the liquid levels L in the corresponding multiple tanks 30A to 30D.

[0045] As shown in Figure 3, the liquid level tube 42 is equipped with a liquid level tube atmospheric vent 47. The liquid level tube atmospheric vent 47 is located above Z1 of the liquid level tube 42. The liquid level tube atmospheric vent 47 is a hole for releasing air inside the liquid level tube 42 to the outside.

[0046] The atmospheric opening section 47 of the liquid level tube is equipped with a moisture-permeable membrane 48. In other words, the liquid level tube 42 is equipped with a moisture-permeable membrane 48. The moisture-permeable membrane 48 is provided on the upper Z1 side inside the liquid level tube 42. The moisture-permeable membrane 48 is provided so as to cover the atmospheric opening section 47 of the liquid level tube from the inside. The moisture-permeable membrane 48 is a membrane that allows air to pass through but not liquid. In this way, the moisture-permeable membrane 48 is provided on the atmospheric opening section 47 of the liquid level tube so as to communicate with the atmosphere.

[0047] As shown in Figure 4, the inlet 43 is provided on the second surface 41B. The inlet 43 is provided so as to protrude forward Y1 from the second surface 41B. The inlet 43 is a component for introducing liquid into the liquid level tube 42. Multiple inlet 43s are components for introducing liquid into corresponding multiple liquid level tubes 42A to 42D.

[0048] The inlet 43 may be configured to penetrate the base 41. A flow path 51 is connected to the inlet 43. This connects the tank 30 and the liquid level pipe 42 via the flow path 51. The flow path 51 allows the liquid from the tank 30 to flow into the liquid level pipe 42. Multiple flow paths 51 allow the liquid from the corresponding multiple tanks 30A to 30D to flow into the liquid level pipes 42A to 42D.

[0049] The connecting portion 44 is provided on the second surface 41B. The connecting portion 44 is provided so as to protrude forward Y1 from the second surface 41B. The connecting portion 44 is a member for connecting the tank 30 and the liquid level pipe 42. Multiple connecting portions 44 are members for connecting the corresponding multiple tanks 30A to 30D and multiple liquid level pipes 42A to 42D.

[0050] The connecting portion 44 may be configured to penetrate the base portion 41. A connecting passage 52 is connected to the connecting portion 44. As a result, the tank 30 and the liquid level pipe 42 are connected via the connecting passage 52. The connecting passage 52 connects the tank atmospheric vent 33 of the tank 30 to the liquid level pipe 42. Multiple connecting passages 52 connect the tank atmospheric vent 33 of the corresponding multiple tanks 30A to 30D to multiple liquid level pipes 42A to 42D.

[0051] As shown in Figures 4 and 5, the reading unit 45 is provided on the first surface 41A side. The multiple liquid level tubes 42A to 42D may be arranged in a direction along the X-axis. The reading unit 45 may be provided on the first surface 41A side in a direction in which the multiple liquid level tubes 42A to 42D are arranged. In other words, the reading unit 45 may be provided on the first surface 41A side in the first width direction X1, further than the multiple liquid level tubes 42A to 42D.

[0052] The reading unit 45 is supported by the support unit 46 on the first surface 41A side. The reading unit 45 is supported by the support unit 46 so as to face a first direction. The first direction is different from the direction perpendicular to the first surface 41A; it is a direction inclined from the direction perpendicular to the first surface 41A. In other words, the first direction is different from the horizontal direction; it is a direction inclined from the horizontal direction.

[0053] The support portion 46 is provided on the first surface 41A. The support portion 46 is provided so as to protrude rearward Y2 from the first surface 41A. The support portion 46 is configured to support the reading portion 45. The support portion 46 supports the reading portion 45 so that the reading portion 45 faces in a first direction.

[0054] The reading unit 45 may be a camera. The reading unit 45 images the liquid level tube 42. The reading unit 45 images multiple liquid level tubes 42A to 42D from a first direction. The reading unit 45 is configured to read the liquid level L of the liquid level tube 42. The reading unit 45 is configured to read the liquid level L of each of the multiple liquid level tubes 42A to 42D.

[0055] The reading unit 45 outputs the captured image data to the control unit 23. In other words, the reading unit 45 outputs the reading result of reading the liquid level L of the liquid level tube 42 to the control unit 23. The reading unit 45 outputs the reading results of reading the liquid levels L of each of the multiple liquid level tubes 42A to 42D to the control unit 23.

[0056] <Liquid level detection and control processing> Next, the liquid level detection control process will be described. The liquid level detection control process is performed by the control unit 23. The liquid level detection control process is performed when the detection conditions are met. The detection conditions may be met when the power to the liquid discharge device 11 is turned on.

[0057] When the detection conditions are met, the control unit 23 outputs a reading instruction to the reading unit 45. As a result, the control unit 23 obtains the reading result from the reading unit 45. The control unit 23 obtains the image data captured by the reading unit 45 from the reading unit 45.

[0058] As shown in Figures 6 and 7, the control unit 23 may generate corrected image data by correcting the acquired image data. Specifically, the control unit 23 corrects the captured image 61 captured by the reading unit 45 to a corrected image 62 from the vertical direction, according to the tilt angle in a first direction with respect to the vertical direction. The corrected image 62 is an image in which the captured image 61 has been corrected to a planar state. The tilt angle is a constant angle. The control unit 23 may also correct the captured image 61 to an enlarged corrected image 62.

[0059] As shown in Figure 6, since the reading unit 45 takes images from a first direction, the captured images 61 of the multiple liquid level tubes 42A to 42D become distorted. Therefore, as shown in Figure 7, the control unit 23 corrects the captured images 61 to corrected images 62, thereby suppressing the distortion of the captured images 61 of the multiple liquid level tubes 42A to 42D.

[0060] The control unit 23 calculates the liquid level L of each of the multiple liquid level tubes 42A to 42D based on the corrected image data. As a result, the control unit 23 can detect the liquid level L in the multiple tanks 30A to 30D based on the reading results from the reading unit 45.

[0061] <Operation and Effects of the First Embodiment> The operation and effects of the first embodiment will now be described. (1-1) The liquid level detection unit 40 includes an inlet section 43 to which a flow path 51 for allowing liquid to flow from the tank 30 into the liquid level tube 42 is connected. The liquid level detection unit 40 includes a reading section 45 that outputs the reading result of reading the liquid level L in the liquid level tube 42 to the control unit 23. The liquid level detection unit 40 includes a base section 41 on which the liquid level tube 42, the inlet section 43, and the reading section 45 are provided. The liquid level tube 42 is translucent, and the height of the reference bottom surface 49 of the liquid level tube 42 is the same as the height of the reference bottom surface 34 of the tank 30. With this configuration, the liquid level L in the tank 30 and the liquid level L in the liquid level tube 42 are the same. Therefore, by reading the liquid level L in the liquid level tube 42 with the reading section 45, the liquid level L in the tank 30 can be read. As a result, the installation location of the liquid level detection unit 40 is not limited to the side of the tank 30. Therefore, even when the liquid level detection unit 40 is installed at a location away from the tank 30, the liquid level L inside the tank 30 can be read. In addition, by installing the liquid level detection unit 40 at a location away from the tank 30, the miniaturization of the tank 30 can be suppressed. Thus, the degree of flexibility in the installation of the liquid level detection unit 40 can be improved.

[0062] (1-2) The liquid level detection unit 40 comprises a plurality of liquid level tubes 42A to 42D and a plurality of inlet ports 43 for allowing liquid to flow from a plurality of tanks 30A to 30D into the plurality of liquid level tubes 42A to 42D, respectively. With this configuration, the reading unit 45 reads the liquid level L that has flowed into the plurality of liquid level tubes 42A to 42D, thereby allowing the liquid level L in the plurality of tanks 30A to 30D corresponding to the plurality of liquid level tubes 42A to 42D to be read.

[0063] (1-3) The liquid level detection unit 40 is equipped with a plurality of reference lines 41C that indicate the reference liquid level L of the liquid level tube 42, arranged in a direction along the Z-axis of the liquid level tube 42. The reading unit 45 is a camera. With this configuration, the liquid level L inside the liquid level tube 42 can be read by imaging the liquid level tube 42 with the camera. This allows the liquid level detection unit 40 to be provided with a simple configuration. In particular, by imaging multiple liquid level tubes 42A to 42D at once with the camera, the liquid levels L inside multiple liquid level tubes 42A to 42D can be read.

[0064] In addition, by imaging multiple reference lines 41C along with the liquid level tube 42 with a camera, it is possible to capture images that improve the detection accuracy of the liquid level L in the liquid level tube 42 based on the multiple reference lines 41C.

[0065] (1-4) The base portion 41 has a first surface 41A. The liquid level tube 42 and the camera are provided on the side of the first surface 41A. The camera images the liquid level tube 42 from a first direction. The first direction is a direction inclined from the vertical direction perpendicular to the first surface 41A. With this configuration, the camera can be placed on the base portion 41 alongside the liquid level tube 42, rather than in front of the liquid level tube 42. This makes it possible to miniaturize the liquid level detection unit 40 in the vertical direction compared to the case where the camera is installed in front of the liquid level tube 42. Therefore, the degree of freedom in installing the liquid level detection unit 40 can be improved.

[0066] (1-5) The liquid level tube 42 has an atmospheric vent 47 at its upper Z1. With this configuration, the atmospheric vent 47 at its upper Z1 allows the liquid level tube 42 to be opened to the atmosphere. This allows liquid to flow smoothly from the tank 30 into the liquid level tube 42.

[0067] (1-6) The liquid level detection unit 40 is equipped with a moisture-permeable membrane 48 that covers the atmospheric opening portion 47 of the liquid level tube. This configuration makes it possible to suppress the leakage of liquid inside the liquid level tube 42 to the outside through the atmospheric opening portion 47 of the liquid level tube.

[0068] (1-7) The liquid level detection unit 40 is equipped with a communication section 44. The communication section 44 connects the liquid level pipe 42 and the tank atmospheric vent section 33. With this configuration, the liquid level pipe 42 and the tank atmospheric vent section 33 can be connected by the provision of the communication section 44. This allows the liquid level pipe 42 to be opened to the atmosphere. Therefore, liquid can flow smoothly from inside the tank 30 into the liquid level pipe 42.

[0069] (1-8) The control unit 23 corrects the captured image 61 taken by the camera to a corrected image 62 from the vertical direction according to the inclination angle in the first direction with respect to the vertical direction. With this configuration, even if the camera captures the liquid level tube 42 from the first direction which is inclined from the vertical direction, the captured image 61 can be corrected to a corrected image 62 from the vertical direction. As a result, the detection accuracy of the liquid level L in the liquid level tube 42 can be improved based on the corrected image 62.

[0070] (1-9) Each of the multiple tanks 30 has an injection section 32 into which liquid is injected. With this configuration, the liquid level L in the tank 30 can be detected, and the liquid can be replenished from the outside via the injection section 32.

[0071] (1-10) Multiple tanks 30A to 30D and the liquid level detection unit 40 may be positioned along the Y-axis, straddling the range of motion of the liquid discharge head 15. With this configuration, multiple tanks 30A to 30D and the liquid level detection unit 40 can be placed at separate positions straddling the range of motion of the liquid discharge head 15. Therefore, the degree of freedom in the installation of the liquid level detection unit 40 can be improved.

[0072] (1-11) At least a portion of the liquid level detection unit 40 overlaps with at least a portion of the multiple tanks 30A to 30D in a front view. With this configuration, the flow path 51 connecting the liquid level detection unit 40 and the multiple tanks 30A to 30D can be shortened compared to the case where the liquid level detection unit 40 and the multiple tanks 30A to 30D do not overlap in a front view. Therefore, the size of the device can be suppressed.

[0073] [Second Embodiment] Next, a second embodiment will be described. In the following description, redundant explanations of the same configuration as in the previously described embodiment will be omitted or simplified, and configurations that differ from those in the previously described embodiment will be described.

[0074] As shown in Figures 8 and 9, the reading unit 45 may be a linear image sensor. The linear image sensor is mounted along the Z-axis relative to the liquid level tube 42. The reading unit 45 may consist of multiple linear image sensors. Each of the multiple linear image sensors is mounted along the Z-axis relative to the multiple liquid level tubes 42A to 42D.

[0075] The reading unit 45 is provided on the first surface 41A side. The reading unit 45 may be attached to the first surface 41A. The reading unit 45 may be provided so as to overlap with the liquid level tube 42 when viewed from a direction perpendicular to the first surface 41A. In other words, the reading unit 45 may be provided so as to overlap with the liquid level tube 42 when viewed from a horizontal direction. The horizontal direction is the direction in which the liquid level inside the liquid level tube 42 intersects the liquid level tube 42 perpendicularly. In this embodiment, the horizontal direction is the direction along the Y axis.

[0076] The linear image sensor receives reflected light from the liquid in the liquid level tube 42, converts the received light into an electrical signal, and outputs a signal corresponding to the amount of received light to the control unit 23. In other words, the reading unit 45 reads the liquid level L in the liquid level tube 42 and outputs the reading result to the control unit 23.

[0077] Thus, the linear image sensor is a sensor that reads the liquid level L of the liquid level tube 42. Multiple linear image sensors are sensors that read the liquid level L of each of the multiple liquid level tubes 42A to 42D.

[0078] The control unit 23 detects the liquid level L of the liquid level tube 42 based on the signal from the reading unit 45. The control unit 23 also detects the liquid level L of each of the multiple liquid level tubes 42A to 42D based on the signal from the reading unit 45.

[0079] <Operation and Effects of the Second Embodiment> The operation and effects of the second embodiment will now be described. (2-1) The reading unit 45 is a linear image sensor. The linear image sensor is installed so as to overlap with the liquid level tube 42 when viewed from a vertical direction perpendicular to the first surface 41A. With this configuration, the liquid level detection unit 40 can be made smaller in the vertical direction compared to when the reading unit 45 is a camera. The liquid level detection unit 40 can also be made smaller in the direction in which multiple liquid level tubes 42A to 42D are lined up, compared to when the reading unit 45 is a camera. Therefore, the degree of freedom in installing the liquid level detection unit 40 can be improved.

[0080] [Third Embodiment] Next, a third embodiment will be described. As shown in Figure 10, in the third embodiment, the liquid level detection unit 40 may be located in the second width direction X2 relative to the transport path 20. The multiple tanks 30A to 30D may be located in the first width direction X1 relative to the transport path 20. The control unit 23 may be located in the second width direction X2 relative to the transport path 20.

[0081] Thus, the multiple tanks 30A to 30D and the liquid level detection unit 40 may be positioned to straddle the transport path 20 in the direction along the X axis. At least a portion of the liquid level detection unit 40 may be positioned to overlap with at least a portion of the multiple tanks 30A to 30D in a side view.

[0082] <Operation and Effects of the Third Embodiment> The operation and effects of the third embodiment will now be described. (3-1) Multiple tanks 30A to 30D and the liquid level detection unit 40 are positioned on either side of the transport path 20 in the direction along the X-axis. With this configuration, multiple tanks 30A to 30D and the liquid level detection unit 40 can be placed at separate positions on either side of the transport path 20. Therefore, the degree of freedom in installing the liquid level detection unit 40 can be improved. In particular, if multiple tanks 30A to 30D are placed in the first width direction X1 relative to the transport path 20, the second width direction X2 relative to the transport path 20 tends to become dead space. Therefore, by placing the liquid level detection unit 40 in the second width direction X2 relative to the transport path 20, it is possible to suppress the enlargement of the liquid discharge device 11.

[0083] (3-2) At least a portion of the liquid level detection unit 40 overlaps with at least a portion of the multiple tanks 30A to 30D in a side view. With this configuration, the flow path 51 connecting the liquid level detection unit 40 and the multiple tanks 30A to 30D can be shortened compared to the case where the liquid level detection unit 40 and the multiple tanks 30A to 30D do not overlap in a side view. Therefore, the size of the device can be suppressed.

[0084] [Fourth Embodiment] Next, a fourth embodiment will be described. As shown in Figure 11, in the fourth embodiment, the liquid level detection unit 40 and tank 30A may be provided in the second width direction X2 relative to the transport path 20. Tanks 30B to 30D may be provided in the first width direction X1 relative to the transport path 20.

[0085] Thus, one or more of the multiple tanks 30A to 30D and the liquid level detection unit 40 may be positioned to straddle the transport path 20 in the direction along the X axis. At least a portion of the liquid level detection unit 40 may be positioned in a side view to overlap with at least a portion of one or more tanks 30B to 30D that are located in the first width direction X1 beyond the transport path 20.

[0086] <Operation and Effects of the Fourth Embodiment> The operation and effects of the fourth embodiment will now be described. (4-1) One or more tanks 30B to 30D and the liquid level detection unit 40 are positioned on either side of the transport path 20 in the direction along the X-axis. With this configuration, one or more tanks 30B to 30D and the liquid level detection unit 40 can be placed at separate positions on either side of the transport path 20. Therefore, the degree of freedom in the installation of the liquid level detection unit 40 can be improved.

[0087] (4-2) At least a portion of the liquid level detection unit 40 may overlap with at least a portion of one or more tanks 30B to 30D in a side view. With this configuration, the flow path 51 connecting the liquid level detection unit 40 and one or more tanks 30B to 30D can be shortened compared to the case where the liquid level detection unit 40 and one or more tanks 30B to 30D do not overlap in a side view. Therefore, the size of the device can be suppressed.

[0088] [Example of changes] This embodiment can be implemented with the following modifications. This embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically.

[0089] In the first embodiment, the support portion 46 may support the reading portion 45 so that the first direction is adjustable. The support portion 46 may also support the reading portion 45 so that the first direction does not change.

[0090] In the first embodiment, the reading unit 45 may be located in the second width direction X2 above the multiple liquid level tubes 42A to 42D. The reading unit 45 may be located above the multiple liquid level tubes 42A to 42D in Z1. The reading unit 45 may be located below the multiple liquid level tubes 42A to 42D in Z2. In other words, the first direction may be a direction inclined from the vertical direction of the first surface 41A in the direction along the Z axis. The first direction may be a direction inclined from the vertical direction of the first surface 41A in both the direction along the X axis and the direction along the Z axis.

[0091] The detection condition may be met when the power to the liquid dispensing device 11 is turned off. The detection condition may be met after the initialization of the liquid dispensing device 11. The detection condition may be met before the start of a print job that prints on at least one sheet of media 99. The detection condition may be met each time a sheet of media 99 is printed. The detection condition may be met after the completion of a print job.

[0092] The detection conditions may be met after maintenance of the liquid discharge head 15. Maintenance may be flushing. Flushing is the operation of discharging liquid from the liquid discharge head 15. Maintenance may also be cleaning. Cleaning is maintenance that forcibly discharges liquid from the liquid discharge head 15, for example by applying negative pressure to the liquid discharge head 15.

[0093] The detection conditions may be met after the liquid has been filled into the tank 30. The detection conditions may be met after the initial filling of the liquid into the tank 30. The detection conditions may be met according to the user's instructions. The detection conditions may be met at predetermined intervals.

[0094] The tank 30 does not need to have an injection section 32, as long as it supplies liquid to the liquid ejection head 15. The tank 30 may be supplied with liquid from an ink cartridge. The tank 30 may be supplied with liquid from an ink tank.

[0095] Each of the multiple tanks 30A to 30D may be positioned in either the first width direction X1 or the second width direction X2 relative to the transport path 20. The liquid discharge device 11 only needs to have one or more tanks 30, and may have one, two, three, or five or more tanks 30. In such cases, the number of liquid level pipes 42, inlets 43, connecting parts 44, flow paths 51, and connecting passages 52 will be the same as the number of tanks 30.

[0096] The liquid level detection unit 40 and the multiple tanks 30A to 30D may be installed at any position. The liquid level detection unit 40 and the multiple tanks 30A to 30D may be installed in a position that does not straddle the transport path 20 in the direction along the X axis. The liquid level detection unit 40 and the multiple tanks 30A to 30D may be installed in a position that does not straddle the movement range of the liquid discharge head 15 in the direction along the Y axis. In the fourth embodiment, the liquid level detection unit 40 may be installed in the first width direction X1 relative to the transport path 20.

[0097] The liquid level detection unit 40 may be installed in a position that does not overlap with the multiple tanks 30A to 30D when viewed from the front. The liquid level detection unit 40 may be installed in a position that does not overlap with the multiple tanks 30A to 30D when viewed from the side.

[0098] The liquid level detection unit 40 may be equipped with a light source capable of illuminating the liquid level tube 42. The light source may be composed of, for example, an LED or a fluorescent lamp. The light source may be provided on the base portion 41. The light source may be provided on the reading portion 45. The light source may be provided on a component different from the liquid level detection unit 40.

[0099] The inlet portion 43 may be provided separately from the base portion 41, or it may be provided integrally with the base portion 41. The communication portion 44 may be provided separately from the base portion 41, or it may be provided integrally with the base portion 41.

[0100] The liquid level tube 42 may be provided on the first surface 41A itself, or on a surface different from the first surface 41A, as long as it is provided on the first surface 41A side. For example, the liquid level tube 42 may be provided in a recess of the first surface 41A. For example, the liquid level tube 42 may be provided in a protrusion of the first surface 41A.

[0101] The liquid level tube 42 does not need to be translucent outside the reading area, as long as the reading area read by the reading unit 45 is translucent. The liquid level tube 42 may be cylindrical or prismatic in shape, as long as it extends in the direction along the Z-axis.

[0102] The base portion 41 may constitute part of the liquid level tube 42. By providing a light-transmitting cover member on the base portion 41, the base portion 41 and the cover member may constitute the liquid level tube 42.

[0103] Multiple reference lines 41C may be provided on the liquid level tube 42 instead of the base portion 41. Multiple reference lines 41C may be provided on both the base portion 41 and the liquid level tube 42. In the second embodiment, the liquid level detection unit 40 does not need to have multiple reference lines 41C.

[0104] If the liquid level pipe 42 is provided with a liquid level pipe atmospheric vent 47, the liquid level detection unit 40 does not need to have a communication section 44 and does not need to communicate with the tank 30. This eliminates the need to provide a communication passage 52 or to route a communication passage 52.

[0105] The liquid level detection unit 40 is equipped with a communication section 44, and if the liquid level pipe 42 and the tank atmospheric vent section 33 are in communication, the liquid level pipe 42 does not need to be provided with an atmospheric vent section 47. This allows the atmospheric vent between the liquid level pipe 42 and the tank 30 to be shared by the tank atmospheric vent section 33. Thus, the liquid level pipe 42 only needs to be open to the atmosphere at the top Z1.

[0106] The moisture-permeable membrane 48 may be provided in the communication section 44. The moisture-permeable membrane 48 may be provided in both the liquid level pipe atmospheric opening section 47 and the communication section 44. The liquid discharge device 11 may include one or more tanks 30, one or more flow paths 51, and one or more connecting passages 52. The liquid level detection unit 40 may include one or more liquid level pipes 42, one or more inlets 43, and one or more connecting parts 44.

[0107] The liquid level detection unit 40 may be positioned in any orientation as long as the liquid level tube 42 extends in a direction along the Z-axis. Therefore, in the above embodiment, the direction along the X-axis and the direction along the Y-axis with respect to the liquid level detection unit 40 may be any direction.

[0108] The specified position may be the position in which the liquid discharge head 15 is positioned when the carriage 16 is positioned in the retraction area 19. The retraction area 19 may be located in the second width direction X2 beyond the printing area 18.

[0109] The liquid ejection head 15 may be of the line type. In the line type, the liquid ejection head 15 is provided in a long length along the width of the medium 99, and printing is performed by ejecting liquid onto the medium 99. In the first embodiment, when the liquid ejection head 15 is of the line type, the liquid level detection unit 40 and the plurality of tanks 30 may be provided so as to straddle a virtual line along the Y axis to which the liquid ejection head 15 extends.

[0110] The linear image sensor constituting the reading unit 45 may be a CMOS image sensor, a MOS (Metal Oxide Semiconductor) image sensor, or a CCD (charge coupled device) image sensor. The image sensor constituting the reading unit 45 may also be an area image sensor.

[0111] The medium 99 may be paper, resin films or sheets, composite films of resin and metal, laminate films, textiles, nonwoven fabrics, metal foils, metal films, ceramic sheets, and clothing.

[0112] The liquid can be any liquid that can be applied to the medium 99 and used for printing on the medium 99. For example, ink may include functional material particles consisting of solids such as pigments and metal particles dissolved, dispersed, or mixed in a solvent, and shall encompass various compositions such as water-based inks, oil-based inks, gel inks, and hot-melt inks.

[0113] As used herein, the expression "at least one of" means one or more of the desired options. For example, as used herein, if there are two options, the expression "at least one of" means either one option or both of the two options. As another example, as used herein, if there are three or more options, the expression "at least one of" means either one option or any combination of two or more options.

[0114] [Note] The following describes the technical concepts and their effects as understood from the embodiments and modifications described above. These technical concepts and their effects can be combined with each other to the extent that they do not contradict each other.

[0115] [1] The liquid level detection unit comprises a liquid level tube extending along the height direction and open to the atmosphere at the top, an inlet section to which a flow path is connected for allowing liquid to flow from a tank connected to a liquid discharge head for discharging liquid into the liquid level tube, a reading section that reads the liquid level in the liquid level tube and outputs the reading result to a control unit, and a base section on which the liquid level tube, the inlet section and the reading section are provided, wherein the liquid level tube is translucent, and the height of the reference bottom surface of the liquid level tube is the same as the height of the reference bottom surface of the tank.

[0116] In this configuration, the liquid level in the tank and the liquid level of the liquid flowing into the liquid level tube are the same. Therefore, by reading the liquid level of the liquid flowing into the liquid level tube, the liquid level in the tank can be read. This means that the installation location of the liquid level detection unit is not limited to the side of the tank. Therefore, the liquid level in the tank can be read even if the liquid level detection unit is installed at a location away from the tank. Thus, the installation flexibility of the liquid level detection unit can be improved.

[0117] [2] The liquid level detection unit may include a plurality of liquid level tubes and a plurality of inlet ports for allowing liquid to flow from a plurality of tanks into the plurality of liquid level tubes, respectively. With this configuration, the reading unit reads the liquid levels of the liquids flowing into multiple liquid level tubes, thereby allowing the liquid levels in multiple tanks corresponding to the multiple liquid level tubes to be read.

[0118] [3] The liquid level detection unit is provided with a plurality of reference lines that indicate the liquid level of the liquid level tube, arranged in the height direction of the liquid level tube, and the reading unit may be a camera. With this configuration, the liquid level inside the liquid level tube can be read by imaging the liquid level tube with a camera. This allows for the installation of a liquid level detection unit with a simple configuration. In addition, by imaging multiple reference lines along with the liquid level tube with the camera, it is possible to capture images that improve the accuracy of detecting the liquid level inside the liquid level tube based on the multiple reference lines.

[0119] [4] The liquid level detection unit described above, wherein the base portion has a first surface, the liquid level tube and the camera are provided on the side of the first surface, the camera images the liquid level tube from a first direction, and the first direction may be a direction inclined from a vertical direction perpendicular to the first surface.

[0120] With this configuration, the camera can be positioned alongside the liquid level tube at the base, rather than directly in front of the tube. This allows for a smaller vertical size of the liquid level detection unit compared to when the camera is mounted directly in front of the tube. Consequently, the flexibility of the liquid level detection unit's placement can be improved.

[0121] [5] The liquid level detection unit described above, wherein the reading unit is a linear image sensor, the base unit has a first surface, the liquid level tube and the linear image sensor are provided on the first surface side, and the linear image sensor may be provided so as to overlap the liquid level tube when viewed from a vertical direction perpendicular to the first surface.

[0122] This configuration allows for miniaturization of the liquid level detection unit in the vertical direction compared to a configuration where the reading unit is a camera. It also allows for miniaturization of the liquid level detection unit in the height direction and in directions intersecting the vertical direction, compared to a configuration where the reading unit is a camera. Therefore, the installation flexibility of the liquid level detection unit can be improved.

[0123] [6] In the above-mentioned liquid level detection unit, the liquid level tube may have an upper portion that is open to the atmosphere. With this configuration, the liquid level tube can be opened to the atmosphere by providing an atmospheric vent above the liquid level tube. This allows liquid to flow smoothly from the tank into the liquid level tube.

[0124] [7] The liquid level detection unit may be provided with a moisture-permeable membrane that covers the atmospheric opening portion of the liquid level tube. This configuration makes it possible to prevent the liquid inside the liquid level tube from leaking to the outside through the atmospheric vent of the liquid level tube.

[0125] [8] The liquid level detection unit may include a communication section that connects the liquid level pipe to a tank atmospheric vent section located above the tank. With this configuration, the liquid level tube and the tank's atmospheric vent are connected by a connecting section. This allows the liquid level tube to be opened to the atmosphere. As a result, liquid can flow smoothly from inside the tank into the liquid level tube.

[0126] [9] The liquid dispensing device comprises a liquid dispensing head for dispensing liquid, a tank connected to the liquid dispensing head, a liquid level detection unit for detecting the liquid level in the tank, a flow path for allowing liquid to flow from the tank to the liquid level detection unit, and a control unit, wherein the liquid level detection unit has a liquid level pipe extending along the height direction and open to the atmosphere at the top, an inlet to which the flow path is connected, a reading unit that outputs a reading result of reading the liquid level in the liquid level pipe to the control unit, and a base portion on which the liquid level pipe, the inlet and the reading unit are provided, wherein the liquid level pipe is translucent, the height of the reference bottom surface of the liquid level pipe is the same as the height of the reference bottom surface of the tank, and the control unit detects the liquid level in the tank based on the reading result from the reading unit. With this configuration, the same effect as in [1] can be achieved.

[0127]

[10] The liquid dispensing device described above, wherein the reading unit is a camera, the base unit has a first surface, the liquid level tube and the camera are provided on the first surface side, the camera images the liquid level tube from a first direction, the first direction is a direction inclined from a vertical direction perpendicular to the first surface, and the control unit may correct the image captured by the camera to a corrected image from the vertical direction according to the inclination angle of the first direction with respect to the vertical direction.

[0128] This configuration can achieve the same effect as [4]. In addition, even if the camera images the liquid level tube from a first direction tilted from the vertical, the captured image can be corrected to a corrected image from the vertical. This makes it possible to improve the accuracy of detecting the liquid level in the liquid level tube based on the corrected image.

[0129]

[11] The liquid discharge device may include a plurality of tanks and a plurality of flow paths, and the liquid level detection unit may include a plurality of liquid level pipes and a plurality of inlet sections. This configuration can achieve the same effect as [2].

[0130]

[12] In the above-mentioned liquid dispensing device, each of the multiple tanks may have an injection section into which the liquid is injected. This configuration allows for the detection of the liquid level in a tank, which can be replenished from the outside via an injection port.

[0131]

[13] The liquid dispensing device described above includes a transport path through which the medium is transported in the transport direction, and one or more of the plurality of tanks and the liquid level detection unit may be positioned to straddle the transport path in a width direction intersecting the transport direction.

[0132] This configuration allows one or more tanks and the liquid level detection unit to be placed at separate locations on either side of the transport path. Therefore, the flexibility of the liquid level detection unit's placement can be improved.

[0133]

[14] In the liquid dispensing device described above, at least a portion of the liquid level detection unit may overlap with at least a portion of the one or more tanks when viewed from the width direction. This configuration allows for a shorter connecting channel between the liquid level detection unit and one or more tanks compared to a case where the liquid level detection unit and one or more tanks do not overlap when viewed from the width direction. Therefore, it is possible to suppress the increase in size of the device.

[0134]

[15] In the liquid dispensing device described above, the liquid dispensing head is movable along the width direction intersecting the height direction, and the plurality of tanks and the liquid level detection unit may be provided at positions that straddle the range of movement of the liquid dispensing head in the front-rear direction intersecting the height direction and the width direction.

[0135] This configuration allows multiple tanks and liquid level detection units to be placed at separate locations that straddle the movement range of the liquid discharge head. Therefore, the degree of freedom in installing the liquid level detection unit can be improved.

[0136]

[16] In the liquid dispensing device described above, at least a portion of the liquid level detection unit may overlap with at least a portion of the plurality of tanks when viewed from the front-to-back direction. This configuration allows for a shorter connection path between the liquid level detection unit and the multiple tanks compared to a configuration where the liquid level detection unit and the multiple tanks do not overlap when viewed from the front or back. Therefore, it is possible to suppress the increase in size of the device. [Explanation of Symbols]

[0137] 11...Liquid dispensing device, 12...Liquid dispensing section, 13...Media support section, 14...Conveying section, 15...Liquid dispensing head, 16...Carriage, 17...Carriage guide, 18...Printing area, 19...Retraction area, 20...Conveying path, 21...Conveying roller pair, 22...Supply path, 23...Control unit, 30...Tank, 30A-30D...Tank, 31...Liquid storage chamber, 32...Injection section, 33...Tank atmospheric vent section, 34...Reference bottom surface, 40...Liquid level detection unit, 41...Base 41A...First surface, 41B...Second surface, 41C...Reference line, 42...Liquid level tube, 42A-42D...Liquid level tube, 43...Inflow part, 44...Communication part, 45...Reading part, 46...Support part, 47...Liquid level tube atmospheric opening part, 48...Moisture permeable membrane, 49 ...Reference bottom surface, 50...Connection path, 51...Flow path, 52...Communication path, 61...Captured image, 62...Corrected image, 99...Medium, L...Liquid level, X1...First width direction, X2...Second width direction, Y1...Front, Y2...Backward, Z1...Upper, Z2...Downward.

Claims

1. A liquid level tube that extends along the vertical direction and opens to the atmosphere at the top, An inlet section to which a flow path is connected for allowing liquid to flow from a tank connected to a liquid discharge head that discharges liquid into the liquid level pipe, A reading unit that reads the liquid level in the liquid level tube and outputs the reading result to the control unit, The base portion on which the liquid level tube, the inlet, and the reading section are provided, Equipped with, The liquid level tube is translucent, The height of the reference bottom surface of the liquid level tube is the same as the height of the reference bottom surface of the tank. A liquid level detection unit characterized by the following features.

2. A liquid level detection unit according to claim 1, Multiple liquid level tubes, Multiple inlet sections for allowing liquid to flow from multiple tanks into multiple liquid level tubes, Equipped with, A liquid level detection unit characterized by the following features.

3. A liquid level detection unit according to claim 1 or claim 2, The liquid level tube is provided with a plurality of reference lines indicating the liquid level reference of the liquid level tube, arranged in the height direction of the liquid level tube. The reading unit is a camera. A liquid level detection unit characterized by the following features.

4. A liquid level detection unit according to claim 3, The base portion has a first surface, The liquid level tube and the camera are provided on the first side. The camera images the liquid level tube from a first direction, The first direction is a direction inclined from the vertical direction perpendicular to the first plane. A liquid level detection unit characterized by the following features.

5. A liquid level detection unit according to claim 1 or claim 2, The reading unit is a linear image sensor, The base portion has a first surface, The liquid level tube and the linear image sensor are provided on the first surface side. The linear image sensor is provided so as to overlap with the liquid level tube when viewed from a vertical direction perpendicular to the first surface. A liquid level detection unit characterized by the following features.

6. A liquid level detection unit according to claim 1 or claim 2, The liquid level tube has an atmospheric outlet at the top. A liquid level detection unit characterized by the following features.

7. A liquid level detection unit according to claim 6, The liquid level tube is equipped with a moisture-permeable membrane that covers the atmospheric opening portion of the liquid level tube. A liquid level detection unit characterized by the following features.

8. A liquid level detection unit according to claim 1 or claim 2, The liquid level pipe is provided with a connecting section that connects it to a tank atmospheric vent located above the tank. A liquid level detection unit characterized by the following features.

9. A liquid dispensing head that dispenses liquid, A tank connected to the liquid discharge head, A liquid level detection unit for detecting the liquid level in the tank, A flow path for flowing liquid from the tank to the liquid level detection unit, Control unit and Equipped with, The liquid level detection unit is A liquid level tube that extends along the vertical direction and opens to the atmosphere at the top, The inlet to which the aforementioned flow path is connected, A reading unit that reads the liquid level in the liquid level tube and outputs the reading result to the control unit, The base portion on which the liquid level tube, the inlet, and the reading section are provided, It has, The liquid level tube is translucent, The height of the reference bottom surface of the liquid level tube is the same as the height of the reference bottom surface of the tank. The control unit detects the liquid level in the tank based on the reading result from the reading unit. A liquid dispensing device characterized by the following features.

10. A liquid dispensing device according to claim 9, The aforementioned reading unit is a camera, The base portion has a first surface, The liquid level tube and the camera are provided on the first side. The camera images the liquid level tube from a first direction, The first direction is a direction inclined from the vertical direction perpendicular to the first plane. The control unit corrects the image captured by the camera to a corrected image from the vertical direction, according to the inclination angle in the first direction with respect to the vertical direction. A liquid dispensing device characterized by the following features.

11. A liquid dispensing device according to claim 9 or claim 10, Multiple of the aforementioned tanks, Multiple of the aforementioned flow paths, Equipped with, The liquid level detection unit is Multiple liquid level tubes, Multiple inlet sections, Having, A liquid dispensing device characterized by the following features.

12. A liquid dispensing device according to claim 11, Each of the aforementioned tanks has an injection port into which liquid is injected. A liquid dispensing device characterized by the following features.

13. A liquid dispensing device according to claim 11, The transport path is provided such that the medium is transported in the transport direction. One or more of the aforementioned tanks and the liquid level detection unit are positioned to straddle the transport path in the width direction intersecting the transport direction. A liquid dispensing device characterized by the following features.

14. A liquid dispensing device according to claim 13, At least a portion of the liquid level detection unit overlaps with at least a portion of the one or more tanks when viewed from the width direction. A liquid dispensing device characterized by the following features.

15. A liquid dispensing device according to claim 11, The liquid dispensing head is movable along the width direction intersecting the height direction, The plurality of tanks and the liquid level detection unit are positioned to straddle the range of movement of the liquid discharge head in the front-to-back direction intersecting the height direction and the width direction. A liquid dispensing device characterized by the following features.

16. A liquid dispensing device according to claim 15, At least a portion of the liquid level detection unit overlaps with at least a portion of the plurality of tanks when viewed from the front-to-back direction. A liquid dispensing device characterized by the following features.

Images